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的关联查询，数据库表除了前面小节中已经定义好的用户表...","2026-09-12T08:29:57.518395Z",[87],[],{"permalink":412,"excerpt":407,"lastModifyTime":413,"phase":116},"\u002Farchives\u002Fmybaitsplus-join-query","2026-09-13T05:25:32.424638Z",[415],{"metadata":416,"spec":417,"status":418,"postCount":96},{"name":87,"creationTimestamp":88},{"displayName":90,"slug":87,"cover":91,"description":92,"priority":27,"hideFromList":93,"preventParentPostCascadeQuery":93},{"permalink":95,"postCount":96,"visiblePostCount":96},{"metadata":420,"spec":423,"status":432,"categories":436},{"name":421,"creationTimestamp":422},"post-mybaitsplus-enum-value-745dbc08","2026-09-12T08:29:56.730649Z",{"title":424,"slug":425,"cover":426,"excerpt":427,"publishTime":429,"categories":430,"tags":431,"priority":27,"pinned":93,"deleted":93,"visible":111,"allowComment":112},"Mybatis Plus 通用枚举（图文讲解）","mybaitsplus-enum-value","\u002Fupload\u002F167359425246371-MHdo.jpg",{"raw":428,"autoGenerate":93},"\r\n大家好，本小节中，我们将讲解 Mybatis Plus 通用枚举的用法。那么，什么是通用枚举呢？之前小节中，我们的用户表有个性别字段 gender，在插入数据时，我们的示例代码大致如下...","2026-09-12T08:29:56.787230Z",[87],[],{"permalink":433,"excerpt":434,"lastModifyTime":435,"phase":116},"\u002Farchives\u002Fmybaitsplus-enum-value","本小节中，我们将讲解 Mybatis Plus 通用枚举的用法。那么，什么是通用枚举呢？之前小节中，我们的用户表有个性别字段 gender，在插入数据时，我们的示例代码大致如下...","2026-09-13T05:25:33.487169Z",[437],{"metadata":438,"spec":439,"status":440,"postCount":96},{"name":87,"creationTimestamp":88},{"displayName":90,"slug":87,"cover":91,"description":92,"priority":27,"hideFromList":93,"preventParentPostCascadeQuery":93},{"permalink":95,"postCount":96,"visiblePostCount":96},{"metadata":442,"spec":445,"status":454,"categories":458},{"name":443,"creationTimestamp":444},"post-mybaitsplus-common-annotation-80f197dc","2026-09-12T08:29:56.056296Z",{"title":446,"slug":447,"cover":448,"excerpt":449,"publishTime":451,"categories":452,"tags":453,"priority":27,"pinned":93,"deleted":93,"visible":111,"allowComment":112},"Mybatis Plus 常用注解（超详细）","mybaitsplus-common-annotation","\u002Fupload\u002F167334634342163-ZyfL.jpg",{"raw":450,"autoGenerate":93},"大家好，本文主要带大家来看下 Mybatis Plus 框架中，使用频率非常高的几个注解及其属性值，因为编写此本教程目的是为了大家快速入门并使用 Mybatis Plus，关于注解更高级的用法请参考官网...","2026-09-12T08:29:56.114067Z",[87],[],{"permalink":455,"excerpt":456,"lastModifyTime":457,"phase":116},"\u002Farchives\u002Fmybaitsplus-common-annotation","本文主要带大家来看下 Mybatis Plus 框架中，使用频率非常高的几个注解及其属性值，因为编写此本教程目的是为了大家快速入门并使用 Mybatis Plus，关于注解更高级的用法请参考官网...","2026-09-13T05:25:33.983128Z",[459],{"metadata":460,"spec":461,"status":462,"postCount":96},{"name":87,"creationTimestamp":88},{"displayName":90,"slug":87,"cover":91,"description":92,"priority":27,"hideFromList":93,"preventParentPostCascadeQuery":93},{"permalink":95,"postCount":96,"visiblePostCount":96},{"metadata":464,"spec":467,"status":476,"categories":479},{"name":465,"creationTimestamp":466},"post-mybaitsplus-code-generator-c984d27c","2026-09-12T08:29:55.452199Z",{"title":468,"slug":469,"cover":470,"excerpt":471,"publishTime":473,"categories":474,"tags":475,"priority":27,"pinned":93,"deleted":93,"visible":111,"allowComment":112},"Mybatis Plus 代码生成器（图文讲解）","mybaitsplus-code-generator","\u002Fupload\u002F167387297654896-aKtE.jpg",{"raw":472,"autoGenerate":93},"本小节中，我们将学习如何使用 Mybatis Plus 的代码生成器。可能有效小伙伴会疑惑，这玩意是干嘛使的？通常在实际项目开发中，如果开发一个功能，我们会先进行表设计，技术方案的确定，技术经理评估 OK 以后，才会进行项目开发，而不是一上来就写代码，跟无头苍蝇一样...","2026-09-12T08:29:55.508709Z",[87],[],{"permalink":477,"excerpt":472,"lastModifyTime":478,"phase":116},"\u002Farchives\u002Fmybaitsplus-code-generator","2026-09-13T05:25:35.131214Z",[480],{"metadata":481,"spec":482,"status":483,"postCount":96},{"name":87,"creationTimestamp":88},{"displayName":90,"slug":87,"cover":91,"description":92,"priority":27,"hideFromList":93,"preventParentPostCascadeQuery":93},{"permalink":95,"postCount":96,"visiblePostCount":96},{"metadata":485,"spec":486,"status":490,"categories":491,"content":496},{"name":210,"creationTimestamp":211},{"title":213,"slug":214,"cover":215,"excerpt":487,"publishTime":218,"categories":488,"tags":489,"priority":27,"pinned":93,"deleted":93,"visible":111,"allowComment":112},{"raw":217,"autoGenerate":93},[87],[],{"permalink":222,"excerpt":223,"lastModifyTime":224,"phase":116},[492],{"metadata":493,"spec":494,"status":495,"postCount":96},{"name":87,"creationTimestamp":88},{"displayName":90,"slug":87,"cover":91,"description":92,"priority":27,"hideFromList":93,"preventParentPostCascadeQuery":93},{"permalink":95,"postCount":96,"visiblePostCount":96},{"content":497,"raw":498},"\u003Cp>\u003C\u002Fp>\n\u003Cp>本小节中，我们将学习如何通过 Mybatis Plus 框架给数据库表新增数据，主要内容思维导图如下：\u003C\u002Fp>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167213988351654-zdcA.jpg\" loading=\"lazy\" title=\"Mybatis Plus 新增数据思维导图\" alt=\"Mybatis Plus 新增数据思维导图\">\u003Cspan class=\"image-caption\">Mybatis Plus 新增数据思维导图\u003C\u002Fspan>\n\u003C\u002Fp>\n\u003Ch2>表结构\u003C\u002Fh2>\n\u003Cp>为了演示新增数据，在前面小节中，我们已经定义好了一个用于测试的用户表， 执行脚本如下：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>DROP TABLE IF EXISTS t_user;\n\nCREATE TABLE `t_user` (\n  `id` bigint(20) UNSIGNED NOT NULL AUTO_INCREMENT COMMENT '主键ID',\n  `name` varchar(30) NOT NULL DEFAULT '' COMMENT '姓名',\n  `age` int(11) NULL DEFAULT NULL COMMENT '年龄',\n  `gender` tinyint(2) NOT NULL DEFAULT 0 COMMENT '性别，0：女 1：男',\n  PRIMARY KEY (`id`)\n) COMMENT = '用户表';\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Ch2>定义实体类\u003C\u002Fh2>\n\u003Cp>定义一个名为 \u003Ccode>User\u003C\u002Fcode> 实体类：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>@Data\n@TableName("t_user")\npublic class User {\n    \u002F**\n     * 主键 ID, @TableId 注解定义字段为表的主键，type 表示主键类型，IdType.AUTO 表示随着数据库 ID 自增\n     *\u002F\n    @TableId(type = IdType.AUTO)\n    private Long id;\n    \u002F**\n     * 姓名\n     *\u002F\n    private String name;\n    \u002F**\n     * 年龄\n     *\u002F\n    private Integer age;\n    \u002F**\n     * 性别\n     *\u002F\n    private Integer gender;\n}\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>讲解一下实体类中用到的注解：\u003C\u002Fp>\n\u003Ch3>@TableName 表名注解\u003C\u002Fh3>\n\u003Cp>作用：\u003Cstrong>标识实体类对应的表\u003C\u002Fstrong>。\u003C\u002Fp>\n\u003Cblockquote>\n\u003Cp>TIP ：\u003C\u002Fp>\n\u003Cul>\n\u003Cli>当实体类名称和实际表名一致时，如实体名为 \u003Ccode>User\u003C\u002Fcode>， 表名为 \u003Ccode>user\u003C\u002Fcode> ，可不用添加该注解，Mybatis Plus 会自动识别并映射到该表。\u003C\u002Fli>\n\u003Cli>当实体类名称和实际表名不一致时，如实体名为 \u003Ccode>User\u003C\u002Fcode>， 表名为 \u003Ccode>t_user\u003C\u002Fcode>，需手动添加该注解，并填写实际表名称。\u003C\u002Fli>\n\u003C\u002Ful>\n\u003C\u002Fblockquote>\n\u003Ch3>@TableId 主键注解\u003C\u002Fh3>\n\u003Cp>作用：\u003Cstrong>声明实体类中的主键对应的字段\u003C\u002Fstrong>。\u003C\u002Fp>\n\u003Ctable>\n\u003Cthead>\n\u003Ctr>\n\u003Cth align=\"left\">属性\u003C\u002Fth>\n\u003Cth align=\"left\">类型\u003C\u002Fth>\n\u003Cth align=\"left\">必须指定\u003C\u002Fth>\n\u003Cth align=\"left\">默认值\u003C\u002Fth>\n\u003Cth align=\"left\">描述\u003C\u002Fth>\n\u003C\u002Ftr>\n\u003C\u002Fthead>\n\u003Ctbody>\n\u003Ctr>\n\u003Ctd align=\"left\">value\u003C\u002Ftd>\n\u003Ctd align=\"left\">String\u003C\u002Ftd>\n\u003Ctd align=\"left\">否\u003C\u002Ftd>\n\u003Ctd align=\"left\">""\u003C\u002Ftd>\n\u003Ctd align=\"left\">主键字段名\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">type\u003C\u002Ftd>\n\u003Ctd align=\"left\">Enum\u003C\u002Ftd>\n\u003Ctd align=\"left\">否\u003C\u002Ftd>\n\u003Ctd align=\"left\">IdType.NONE\u003C\u002Ftd>\n\u003Ctd align=\"left\">指定主键类型\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003C\u002Ftbody>\n\u003C\u002Ftable>\n\u003Ch3>IdType 主键类型\u003C\u002Fh3>\n\u003Ctable>\n\u003Cthead>\n\u003Ctr>\n\u003Cth align=\"left\">值\u003C\u002Fth>\n\u003Cth align=\"left\">描述\u003C\u002Fth>\n\u003C\u002Ftr>\n\u003C\u002Fthead>\n\u003Ctbody>\n\u003Ctr>\n\u003Ctd align=\"left\">AUTO\u003C\u002Ftd>\n\u003Ctd align=\"left\">数据库 ID 自增\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">NONE\u003C\u002Ftd>\n\u003Ctd align=\"left\">无状态，该类型为未设置主键类型（默认）\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">INPUT\u003C\u002Ftd>\n\u003Ctd align=\"left\">插入数据前，需自行设置主键的值\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">ASSIGN_ID\u003C\u002Ftd>\n\u003Ctd align=\"left\">分配 ID(主键类型为 Number(Long 和 Integer)或 String)(since 3.3.0),使用接口\u003Ccode>IdentifierGenerator\u003C\u002Fcode>的方法\u003Ccode>nextId\u003C\u002Fcode>(默认实现类为\u003Ccode>DefaultIdentifierGenerator\u003C\u002Fcode>雪花算法)\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">ASSIGN_UUID\u003C\u002Ftd>\n\u003Ctd align=\"left\">分配 UUID,主键类型为 String(since 3.3.0),使用接口\u003Ccode>IdentifierGenerator\u003C\u002Fcode>的方法\u003Ccode>nextUUID\u003C\u002Fcode> (默认 default 方法)\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">~~ID_WORKER~~\u003C\u002Ftd>\n\u003Ctd align=\"left\">分布式全局唯一 ID 长整型类型 (推荐使用 \u003Ccode>ASSIGN_ID\u003C\u002Fcode>)\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">~~UUID~~\u003C\u002Ftd>\n\u003Ctd align=\"left\">32 位 UUID 字符串 (推荐使用 \u003Ccode>ASSIGN_UUID\u003C\u002Fcode>)\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">~~ID_WORKER_STR~~\u003C\u002Ftd>\n\u003Ctd align=\"left\">分布式全局唯一 ID 字符串类型 (推荐使用 \u003Ccode>ASSIGN_ID\u003C\u002Fcode>)\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003C\u002Ftbody>\n\u003C\u002Ftable>\n\u003Ch2>开始新增数据\u003C\u002Fh2>\n\u003Cp>测试表准备好后，我们准备开始演示新增数据。实际上，Mybatis Plus 对 Mapper 层和 Service 层都将常见的增删改查操作都封装好了，只需简单的继承，即可轻松搞定对数据的增删改查，本文重点讲解新增数据这块。\u003C\u002Fp>\n\u003Ch3>Mapper 层\u003C\u002Fh3>\n\u003Cp>定义一个 \u003Ccode>UserMapper\u003C\u002Fcode> , 让其继承 \u003Ccode>BaseMapper\u003C\u002Fcode> :\u003C\u002Fp>\n\u003Cpre>\u003Ccode>public interface UserMapper extends BaseMapper<User> {\n}\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>然后，注入 Mapper :\u003C\u002Fp>\n\u003Cpre>\u003Ccode>@Autowired\nprivate UserMapper userMapper;\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>\u003Ccode>BaseMapper\u003C\u002Fcode> 提供的新增方法仅一个 \u003Ccode>insert()\u003C\u002Fcode> 方法：\u003C\u002Fp>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167220330351372-ApDw.jpg\" loading=\"lazy\">\n\u003C\u002Fp>\n\u003Cp>我们通过它测试一下添加数据，并获取主键 ID :\u003C\u002Fp>\n\u003Cpre>\u003Ccode>User user = new User();\nuser.setName("张三");\nuser.setAge(30);\nuser.setGender(1);\n\nuserMapper.insert(user);\n\n\u002F\u002F 获取插入数据的主键 ID\nLong id = user.getId();\n\nSystem.out.println("id:" + id);\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>怎么样，是不是非常简单呢！\u003C\u002Fp>\n\u003Ch3>Service 层\u003C\u002Fh3>\n\u003Cp>Mybatis Plus 同样也封装了通用的 Service 层 CRUD 操作，并且提供了更丰富的方法。接下来，我们上手看 Service 层的代码结构，如下图：\u003C\u002Fp>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167204808139593-dWMf.jpg\" loading=\"lazy\" title=\"定义 Service 层\" alt=\"定义 Service 层\">\u003Cspan class=\"image-caption\">定义 Service 层\u003C\u002Fspan>\n\u003C\u002Fp>\n\u003Cp>先定义 \u003Ccode>UserService\u003C\u002Fcode> 接口 ，让其继承自 \u003Ccode>IService\u003C\u002Fcode>:\u003C\u002Fp>\n\u003Cpre>\u003Ccode>public interface UserService extends IService<User> {\n}\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>再定义实现类 \u003Ccode>UserServiceImpl\u003C\u002Fcode>，让其继承自 \u003Ccode>ServiceImpl\u003C\u002Fcode>, 同时实现 \u003Ccode>UserService\u003C\u002Fcode> 接口，这样就可以让 \u003Ccode>UserService\u003C\u002Fcode> 拥有了基础通用的 CRUD 功能，当然，实际开发中，业务会更加复杂，就需要向 \u003Ccode>IService\u003C\u002Fcode> 接口自定义方法并实现:\u003C\u002Fp>\n\u003Cpre>\u003Ccode>@Service\npublic class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService {\n}\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>注入 \u003Ccode>UserService\u003C\u002Fcode> :\u003C\u002Fp>\n\u003Cpre>\u003Ccode>@Autowired\nprivate UserService userService;\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>与 Mapper 层不同的是，Service 层的新增方法均以 \u003Ccode>save\u003C\u002Fcode> 开头，并且功能更丰富，来看看都提供了哪些方法：\u003C\u002Fp>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167204984846713-tDOT.jpg\" loading=\"lazy\" title=\"新增数据共有 6 个方法\" alt=\"新增数据共有 6 个方法\">\u003Cspan class=\"image-caption\">新增数据共有 6 个方法\u003C\u002Fspan>\n\u003C\u002Fp>\n\u003Cp>简单解释下每个方法的作用，以作了解：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>\u002F\u002F 新增数据\nsava(T) : boolean\n\u002F\u002F 伪批量插入，实际上是通过 for 循环一条一条的插入\nsavaBatch(Collection<T>) : boolean\n\u002F\u002F 伪批量插入，int 表示批量提交数，默认为 1000\nsavaBatch(Collection<T>, int) : boolean\n\u002F\u002F 新增或更新(单条数据)\nsaveOrUpdate(T) : boolean\n\u002F\u002F 批量新增或更新\nsaveOrUpdateBatch(Collection<T>) : boolean\n\u002F\u002F 批量新增或更新(可指定批量提交数)\nsaveOrUpdateBatch(Collection<T>, int) : boolean\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>大致看完后，上手测试一下。\u003C\u002Fp>\n\u003Ch4>sava(T)\u003C\u002Fh4>\n\u003Cp>\u003Cstrong>简单的新增数据\u003C\u002Fstrong>，示例代码如下：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>\u002F\u002F 新增数据\n\u002F\u002F 实际执行 SQL : INSERT INTO user ( name, age, gender ) VALUES ( '张三111', 30, 1 )\nUser user = new User();\nuser.setName("张三111");\nuser.setAge(30);\nuser.setGender(1);\n\nboolean isSuccess = userService.save(user);\n\n\u002F\u002F 返回主键ID\nLong id = user.getId();\nSystem.out.println("isSuccess:" + isSuccess);\nSystem.out.println("主键 ID: " + id);\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Ch4>savaBatch(Collection\u003CT>)\u003C\u002Fh4>\n\u003Cp>\u003Cstrong>伪批量插入\u003C\u002Fstrong>，注意，命名虽然包含了批量的意思，但这不是真的批量插入，不信的话，我们来实际测试一下：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>\u002F\u002F 批量插入\nList<User> users = new ArrayList<>();\nfor (int i = 0; i < 5; i++) {\n    User user = new User();\n    user.setName("张三" + i);\n    user.setAge(i);\n    user.setGender(1);\n    users.add(user);\n}\nboolean isSuccess = userService.saveBatch(users);\nSystem.out.println("isSuccess:" + isSuccess);\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>执行代码，实际执行的 SQL 如下：\u003C\u002Fp>\n\u003Cblockquote>\n\u003Cp>TIP : 如何打印实际执行的 SQL, 可参考之前小节的 《Mybatis Plus 打印 SQL 语句（包含执行耗时）》\u003Cspan>\u003Csvg xmlns=\"http:\u002F\u002Fwww.w3.org\u002F2000\u002Fsvg\" style=\"color: #aaa; margin-left: 3px;\" aria-hidden=\"true\" focusable=\"false\" x=\"0px\" y=\"0px\" viewBox=\"0 0 100 100\" width=\"15\" height=\"15\" class=\"icon outbound\">\u003Cpath fill=\"currentColor\" d=\"M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z\">\u003C\u002Fpath> \u003Cpolygon fill=\"currentColor\" points=\"45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9\">\u003C\u002Fpolygon>\u003C\u002Fsvg> \u003Cspan class=\"sr-only\">\u003C\u002Fspan>\u003C\u002Fspan>。\u003C\u002Fp>\n\u003C\u002Fblockquote>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167211863047181-DEdJ.jpg\" loading=\"lazy\" title=\"批量插入输入 SQL 打印\" alt=\"批量插入输入 SQL 打印\">\u003Cspan class=\"image-caption\">批量插入输入 SQL 打印\u003C\u002Fspan>\n\u003C\u002Fp>\n\u003Cp>可以看到，并不是 \u003Ccode>insert into user (xxx) values (xxx),(xxx),(xxx)\u003C\u002Fcode> 这种批量形式，还是一条一条插入的。\u003C\u002Fp>\n\u003Ch5>批量新增源码分析\u003C\u002Fh5>\n\u003Cp>我们来看下源码, 内部的\u003Ccode>saveBatch()\u003C\u002Fcode> 方法默认的批量提交阀值参数，数值为 1000， 即达到 1000 条批量提交一次，继续点进去看：：\u003C\u002Fp>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167212963055320-ODNh.jpg\" loading=\"lazy\">\n\u003C\u002Fp>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167211902799533.jpg\" loading=\"lazy\" title=\"源码分析\" alt=\"源码分析\">\u003Cspan class=\"image-caption\">源码分析\u003C\u002Fspan>\n\u003C\u002Fp>\n\u003Cpre>\u003Ccode>public boolean saveBatch(Collection<T> entityList, int batchSize) {\n        \u002F\u002F 获取预编译的插入 SQL\n        String sqlStatement = this.getSqlStatement(SqlMethod.INSERT_ONE);\n        \u002F\u002F for 循环执行 insert\n        return this.executeBatch(entityList, batchSize, (sqlSession, entity) -> {\n            sqlSession.insert(sqlStatement, entity);\n        });\n    }\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>再看下 \u003Ccode>SqlMethod.INSERT_ONE\u003C\u002Fcode> 这个枚举，描述信息为\u003Cem>插入一条数据\u003C\u002Fem>：\u003C\u002Fp>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167213598609592-GcND.jpg\" loading=\"lazy\">\n\u003C\u002Fp>\n\u003Cp>继续往 \u003Ccode>executeBatch()\u003C\u002Fcode> 方法里看，瞅瞅它这个批量到底是怎么处理的，具体每行代码的意思，都加了注释：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>    public static <E> boolean executeBatch(Class<?> entityClass, Log log, Collection<E> list, int batchSize, BiConsumer<SqlSession, E> consumer) {\n    \t\u002F\u002F 断言需要批处理数据集大小不等于1\n        Assert.isFalse(batchSize < 1, "batchSize must not be less than one", new Object[0]);\n        \u002F\u002F 判空数据集，若不为空，则开始执行批量处理\n        return !CollectionUtils.isEmpty(list) && executeBatch(entityClass, log, (sqlSession) -> {\n        \t\n            int size = list.size();\n            \u002F\u002F 将批处理大小与传入的操作集合大小进行比较，取最小的那个\n            int idxLimit = Math.min(batchSize, size);\n            int i = 1;\n            \u002F\u002F 迭代器循环\n            for(Iterator var7 = list.iterator(); var7.hasNext(); ++i) {\n            \t\u002F\u002F 获取当前需要执行的数据库操作\n                E element = var7.next();\n                \u002F\u002F 回调 sqlSession.insert() 方法\n                consumer.accept(sqlSession, element);\n                \u002F\u002F 判断是否达到需要批处理的阀值\n                if (i == idxLimit) {\n                \t\u002F\u002F 开始批处理，此方法执行并清除缓存在 JDBC 驱动类中的执行语句\n                    sqlSession.flushStatements();\n                    idxLimit = Math.min(idxLimit + batchSize, size);\n                }\n            }\n        });\n    }\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>看完就明白了，相比较自己手动 \u003Ccode>for\u003C\u002Fcode> 循环执行插入，Mybatis Plus 这个伪批量插入性能会更好些，内部会将每次的插入语句缓存起来，等到达到 1000 条的时候，才会统一推给数据库，虽然最终在数据库那边还是一条一条的执行 INSERT，但还是在和数据库交互的 IO 上做了优化。\u003C\u002Fp>\n\u003Ch4>savaBatch(Collection\u003CT>, int)\u003C\u002Fh4>\n\u003Cp>多了个 \u003Ccode>batchSize\u003C\u002Fcode> 参数，可以手动指定批处理的大小，即多少 SQL 操作执行一次，默认为 1000。\u003C\u002Fp>\n\u003Ch4>saveOrUpdate(T)\u003C\u002Fh4>\n\u003Cp>\u003Cstrong>保存或者更新\u003C\u002Fstrong>。即当你需要执行的数据，数据库中不存在时，就执行插入操作：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>\u002F\u002F 实际执行 SQL : INSERT INTO user ( name, age, gender ) VALUES ( '张小三', 60, 1 )\nUser user = new User();\nuser.setName("张小三");\nuser.setAge(60);\nuser.setGender(1);\nuserService.saveOrUpdate(user);\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>当你需要执行的数据，数据库中已存在时，就执行更新操作。框架是如何判断该记录是否存在呢？ 如设置了主键 ID，因为主键 ID 必须是唯一的，Mybatis Plus 会先执行查询操作，判断数据是否存在，存在即执行更新，否则，执行插入操作：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>User user = new User();\n\u002F\u002F 设置了主键字段\nuser.setId(21L);\nuser.setName("张小三");\nuser.setAge(60);\nuser.setGender(1);\nuserService.saveOrUpdate(user);\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>具体执行 SQL 如下：\u003C\u002Fp>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167212563888187-JSqc.jpg\" loading=\"lazy\">\n\u003C\u002Fp>\n\u003Ch4>saveOrUpdateBatch(Collection\u003CT>)\u003C\u002Fh4>\n\u003Cp>批量保存或者更新，示例代码如下：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>List<User> users = new ArrayList<>();\nfor (int i = 0; i < 5; i++) {\n    User user = new User();\n    user.setId(Long.valueOf(i));\n    user.setName("张三" + i);\n    user.setAge(i+1);\n    user.setGender(1);\n    users.add(user);\n}\nuserService.saveOrUpdateBatch(users);\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Ch4>saveOrUpdateBatch(Collection\u003CT>, int)\u003C\u002Fh4>\n\u003Cp>批量保存或者更新（可手动指定批量大小），示例代码如下：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>List<User> users = new ArrayList<>();\nfor (int i = 0; i < 5; i++) {\n    User user = new User();\n    user.setId(Long.valueOf(i));\n    user.setName("张三" + i);\n    user.setAge(i+1);\n    user.setGender(1);\n    users.add(user);\n}\nuserService.saveOrUpdateBatch(users, 100);\n\u003C\u002Fcode>\u003C\u002Fpre>\n13:Tbb50,\u003Cp>\u003C\u002Fp>\n\u003Cp>本小节中，我们将学习如何通过 Mybatis Plus 框架给数据库表新增数据，主要内容思维导图如下：\u003C\u002Fp>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167213988351654-zdcA.jpg\" loading=\"lazy\" title=\"Mybatis Plus 新增数据思维导图\" alt=\"Mybatis Plus 新增数据思维导图\">\u003C\u002Fdiv>\u003Cspan class=\"image-caption\">Mybatis Plus 新增数据思维导图\u003C\u002Fspan>\n\u003C\u002Fp>\n\u003Ch2 id=\"toc-0\">表结构\u003C\u002Fh2>\n\u003Cp>为了演示新增数据，在前面小节中，我们已经定义好了一个用于测试的用户表， 执行脚本如下：\u003C\u002Fp>\n\u003Cdiv class=\"language-sql\" data-ext=\"sql\" data-code=\"DROP%20TABLE%20IF%20EXISTS%20t_user%3B%0A%0ACREATE%20TABLE%20%60t_user%60%20(%0A%20%20%60id%60%20bigint(20)%20UNSIGNED%20NOT%20NULL%20AUTO_INCREMENT%20COMMENT%20'%E4%B8%BB%E9%94%AEID'%2C%0A%20%20%60name%60%20varchar(30)%20NOT%20NULL%20DEFAULT%20''%20COMMENT%20'%E5%A7%93%E5%90%8D'%2C%0A%20%20%60age%60%20int(11)%20NULL%20DEFAULT%20NULL%20COMMENT%20'%E5%B9%B4%E9%BE%84'%2C%0A%20%20%60gender%60%20tinyint(2)%20NOT%20NULL%20DEFAULT%200%20COMMENT%20'%E6%80%A7%E5%88%AB%EF%BC%8C0%EF%BC%9A%E5%A5%B3%201%EF%BC%9A%E7%94%B7'%2C%0A%20%20PRIMARY%20KEY%20(%60id%60)%0A)%20COMMENT%20%3D%20'%E7%94%A8%E6%88%B7%E8%A1%A8'%3B%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-sql\">\u003Cspan class=\"token keyword\">DROP\u003C\u002Fspan> \u003Cspan class=\"token keyword\">TABLE\u003C\u002Fspan> \u003Cspan class=\"token keyword\">IF\u003C\u002Fspan> \u003Cspan class=\"token keyword\">EXISTS\u003C\u002Fspan> t_user\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\n\u003Cspan class=\"token keyword\">CREATE\u003C\u002Fspan> \u003Cspan class=\"token keyword\">TABLE\u003C\u002Fspan> \u003Cspan class=\"token identifier\">\u003Cspan class=\"token punctuation\">`\u003C\u002Fspan>t_user\u003Cspan class=\"token punctuation\">`\u003C\u002Fspan>\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\n  \u003Cspan class=\"token identifier\">\u003Cspan class=\"token punctuation\">`\u003C\u002Fspan>id\u003Cspan class=\"token punctuation\">`\u003C\u002Fspan>\u003C\u002Fspan> \u003Cspan class=\"token keyword\">bigint\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token number\">20\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token keyword\">UNSIGNED\u003C\u002Fspan> \u003Cspan class=\"token operator\">NOT\u003C\u002Fspan> \u003Cspan class=\"token boolean\">NULL\u003C\u002Fspan> \u003Cspan class=\"token keyword\">AUTO_INCREMENT\u003C\u002Fspan> \u003Cspan class=\"token keyword\">COMMENT\u003C\u002Fspan> \u003Cspan class=\"token string\">'主键ID'\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan>\n  \u003Cspan class=\"token identifier\">\u003Cspan class=\"token punctuation\">`\u003C\u002Fspan>name\u003Cspan class=\"token punctuation\">`\u003C\u002Fspan>\u003C\u002Fspan> \u003Cspan class=\"token keyword\">varchar\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token number\">30\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token operator\">NOT\u003C\u002Fspan> \u003Cspan class=\"token boolean\">NULL\u003C\u002Fspan> \u003Cspan class=\"token keyword\">DEFAULT\u003C\u002Fspan> \u003Cspan class=\"token string\">''\u003C\u002Fspan> \u003Cspan class=\"token keyword\">COMMENT\u003C\u002Fspan> \u003Cspan class=\"token string\">'姓名'\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan>\n  \u003Cspan class=\"token identifier\">\u003Cspan class=\"token punctuation\">`\u003C\u002Fspan>age\u003Cspan class=\"token punctuation\">`\u003C\u002Fspan>\u003C\u002Fspan> \u003Cspan class=\"token keyword\">int\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token number\">11\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token boolean\">NULL\u003C\u002Fspan> \u003Cspan class=\"token keyword\">DEFAULT\u003C\u002Fspan> \u003Cspan class=\"token boolean\">NULL\u003C\u002Fspan> \u003Cspan class=\"token keyword\">COMMENT\u003C\u002Fspan> \u003Cspan class=\"token string\">'年龄'\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan>\n  \u003Cspan class=\"token identifier\">\u003Cspan class=\"token punctuation\">`\u003C\u002Fspan>gender\u003Cspan class=\"token punctuation\">`\u003C\u002Fspan>\u003C\u002Fspan> \u003Cspan class=\"token keyword\">tinyint\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token number\">2\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token operator\">NOT\u003C\u002Fspan> \u003Cspan class=\"token boolean\">NULL\u003C\u002Fspan> \u003Cspan class=\"token keyword\">DEFAULT\u003C\u002Fspan> \u003Cspan class=\"token number\">0\u003C\u002Fspan> \u003Cspan class=\"token keyword\">COMMENT\u003C\u002Fspan> \u003Cspan class=\"token string\">'性别，0：女 1：男'\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan>\n  \u003Cspan class=\"token keyword\">PRIMARY\u003C\u002Fspan> \u003Cspan class=\"token keyword\">KEY\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token identifier\">\u003Cspan class=\"token punctuation\">`\u003C\u002Fspan>id\u003Cspan class=\"token punctuation\">`\u003C\u002Fspan>\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\n\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token keyword\">COMMENT\u003C\u002Fspan> \u003Cspan class=\"token operator\">=\u003C\u002Fspan> \u003Cspan class=\"token string\">'用户表'\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Ch2 id=\"toc-1\">定义实体类\u003C\u002Fh2>\n\u003Cp>定义一个名为 \u003Ccode>User\u003C\u002Fcode> 实体类：\u003C\u002Fp>\n\u003Cdiv class=\"language-java\" data-ext=\"java\" data-code=\"%40Data%0A%40TableName(%22t_user%22)%0Apublic%20class%20User%20%7B%0A%20%20%20%20%2F**%0A%20%20%20%20%20*%20%E4%B8%BB%E9%94%AE%20ID%2C%20%40TableId%20%E6%B3%A8%E8%A7%A3%E5%AE%9A%E4%B9%89%E5%AD%97%E6%AE%B5%E4%B8%BA%E8%A1%A8%E7%9A%84%E4%B8%BB%E9%94%AE%EF%BC%8Ctype%20%E8%A1%A8%E7%A4%BA%E4%B8%BB%E9%94%AE%E7%B1%BB%E5%9E%8B%EF%BC%8CIdType.AUTO%20%E8%A1%A8%E7%A4%BA%E9%9A%8F%E7%9D%80%E6%95%B0%E6%8D%AE%E5%BA%93%20ID%20%E8%87%AA%E5%A2%9E%0A%20%20%20%20%20*%2F%0A%20%20%20%20%40TableId(type%20%3D%20IdType.AUTO)%0A%20%20%20%20private%20Long%20id%3B%0A%20%20%20%20%2F**%0A%20%20%20%20%20*%20%E5%A7%93%E5%90%8D%0A%20%20%20%20%20*%2F%0A%20%20%20%20private%20String%20name%3B%0A%20%20%20%20%2F**%0A%20%20%20%20%20*%20%E5%B9%B4%E9%BE%84%0A%20%20%20%20%20*%2F%0A%20%20%20%20private%20Integer%20age%3B%0A%20%20%20%20%2F**%0A%20%20%20%20%20*%20%E6%80%A7%E5%88%AB%0A%20%20%20%20%20*%2F%0A%20%20%20%20private%20Integer%20gender%3B%0A%7D%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-java\">\u003Cspan class=\"token annotation punctuation\">@Data\u003C\u002Fspan>\n\u003Cspan class=\"token annotation punctuation\">@TableName\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token string\">\"t_user\"\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\n\u003Cspan class=\"token keyword\">public\u003C\u002Fspan> \u003Cspan class=\"token keyword\">class\u003C\u002Fspan> \u003Cspan class=\"token class-name\">User\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">{\u003C\u002Fspan>\n    \u003Cspan class=\"token comment\">\u002F**\n     * 主键 ID, @TableId 注解定义字段为表的主键，type 表示主键类型，IdType.AUTO 表示随着数据库 ID 自增\n     *\u002F\u003C\u002Fspan>\n    \u003Cspan class=\"token annotation punctuation\">@TableId\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>type \u003Cspan class=\"token operator\">=\u003C\u002Fspan> \u003Cspan class=\"token class-name\">IdType\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token constant\">AUTO\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\n    \u003Cspan class=\"token keyword\">private\u003C\u002Fspan> \u003Cspan class=\"token class-name\">Long\u003C\u002Fspan> id\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n    \u003Cspan class=\"token comment\">\u002F**\n     * 姓名\n     *\u002F\u003C\u002Fspan>\n    \u003Cspan class=\"token keyword\">private\u003C\u002Fspan> \u003Cspan class=\"token class-name\">String\u003C\u002Fspan> name\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n    \u003Cspan class=\"token comment\">\u002F**\n     * 年龄\n     *\u002F\u003C\u002Fspan>\n    \u003Cspan class=\"token keyword\">private\u003C\u002Fspan> \u003Cspan class=\"token class-name\">Integer\u003C\u002Fspan> age\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n    \u003Cspan class=\"token comment\">\u002F**\n     * 性别\n     *\u002F\u003C\u002Fspan>\n    \u003Cspan class=\"token keyword\">private\u003C\u002Fspan> \u003Cspan class=\"token class-name\">Integer\u003C\u002Fspan> gender\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token punctuation\">}\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>讲解一下实体类中用到的注解：\u003C\u002Fp>\n\u003Ch3 id=\"toc-2\">@TableName 表名注解\u003C\u002Fh3>\n\u003Cp>作用：\u003Cstrong>标识实体类对应的表\u003C\u002Fstrong>。\u003C\u002Fp>\n\u003Cblockquote>\n\u003Cp>TIP ：\u003C\u002Fp>\n\u003Cul>\n\u003Cli>当实体类名称和实际表名一致时，如实体名为 \u003Ccode>User\u003C\u002Fcode>， 表名为 \u003Ccode>user\u003C\u002Fcode> ，可不用添加该注解，Mybatis Plus 会自动识别并映射到该表。\u003C\u002Fli>\n\u003Cli>当实体类名称和实际表名不一致时，如实体名为 \u003Ccode>User\u003C\u002Fcode>， 表名为 \u003Ccode>t_user\u003C\u002Fcode>，需手动添加该注解，并填写实际表名称。\u003C\u002Fli>\n\u003C\u002Ful>\n\u003C\u002Fblockquote>\n\u003Ch3 id=\"toc-3\">@TableId 主键注解\u003C\u002Fh3>\n\u003Cp>作用：\u003Cstrong>声明实体类中的主键对应的字段\u003C\u002Fstrong>。\u003C\u002Fp>\n\u003Ctable>\n\u003Cthead>\n\u003Ctr>\n\u003Cth align=\"left\">属性\u003C\u002Fth>\n\u003Cth align=\"left\">类型\u003C\u002Fth>\n\u003Cth align=\"left\">必须指定\u003C\u002Fth>\n\u003Cth align=\"left\">默认值\u003C\u002Fth>\n\u003Cth align=\"left\">描述\u003C\u002Fth>\n\u003C\u002Ftr>\n\u003C\u002Fthead>\n\u003Ctbody>\n\u003Ctr>\n\u003Ctd align=\"left\">value\u003C\u002Ftd>\n\u003Ctd align=\"left\">String\u003C\u002Ftd>\n\u003Ctd align=\"left\">否\u003C\u002Ftd>\n\u003Ctd align=\"left\">""\u003C\u002Ftd>\n\u003Ctd align=\"left\">主键字段名\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">type\u003C\u002Ftd>\n\u003Ctd align=\"left\">Enum\u003C\u002Ftd>\n\u003Ctd align=\"left\">否\u003C\u002Ftd>\n\u003Ctd align=\"left\">IdType.NONE\u003C\u002Ftd>\n\u003Ctd align=\"left\">指定主键类型\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003C\u002Ftbody>\n\u003C\u002Ftable>\n\u003Ch3 id=\"toc-4\">IdType 主键类型\u003C\u002Fh3>\n\u003Ctable>\n\u003Cthead>\n\u003Ctr>\n\u003Cth align=\"left\">值\u003C\u002Fth>\n\u003Cth align=\"left\">描述\u003C\u002Fth>\n\u003C\u002Ftr>\n\u003C\u002Fthead>\n\u003Ctbody>\n\u003Ctr>\n\u003Ctd align=\"left\">AUTO\u003C\u002Ftd>\n\u003Ctd align=\"left\">数据库 ID 自增\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">NONE\u003C\u002Ftd>\n\u003Ctd align=\"left\">无状态，该类型为未设置主键类型（默认）\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">INPUT\u003C\u002Ftd>\n\u003Ctd align=\"left\">插入数据前，需自行设置主键的值\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">ASSIGN_ID\u003C\u002Ftd>\n\u003Ctd align=\"left\">分配 ID(主键类型为 Number(Long 和 Integer)或 String)(since 3.3.0),使用接口\u003Ccode>IdentifierGenerator\u003C\u002Fcode>的方法\u003Ccode>nextId\u003C\u002Fcode>(默认实现类为\u003Ccode>DefaultIdentifierGenerator\u003C\u002Fcode>雪花算法)\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">ASSIGN_UUID\u003C\u002Ftd>\n\u003Ctd align=\"left\">分配 UUID,主键类型为 String(since 3.3.0),使用接口\u003Ccode>IdentifierGenerator\u003C\u002Fcode>的方法\u003Ccode>nextUUID\u003C\u002Fcode> (默认 default 方法)\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">~~ID_WORKER~~\u003C\u002Ftd>\n\u003Ctd align=\"left\">分布式全局唯一 ID 长整型类型 (推荐使用 \u003Ccode>ASSIGN_ID\u003C\u002Fcode>)\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">~~UUID~~\u003C\u002Ftd>\n\u003Ctd align=\"left\">32 位 UUID 字符串 (推荐使用 \u003Ccode>ASSIGN_UUID\u003C\u002Fcode>)\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">~~ID_WORKER_STR~~\u003C\u002Ftd>\n\u003Ctd align=\"left\">分布式全局唯一 ID 字符串类型 (推荐使用 \u003Ccode>ASSIGN_ID\u003C\u002Fcode>)\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003C\u002Ftbody>\n\u003C\u002Ftable>\n\u003Ch2 id=\"toc-5\">开始新增数据\u003C\u002Fh2>\n\u003Cp>测试表准备好后，我们准备开始演示新增数据。实际上，Mybatis Plus 对 Mapper 层和 Service 层都将常见的增删改查操作都封装好了，只需简单的继承，即可轻松搞定对数据的增删改查，本文重点讲解新增数据这块。\u003C\u002Fp>\n\u003Ch3 id=\"toc-6\">Mapper 层\u003C\u002Fh3>\n\u003Cp>定义一个 \u003Ccode>UserMapper\u003C\u002Fcode> , 让其继承 \u003Ccode>BaseMapper\u003C\u002Fcode> :\u003C\u002Fp>\n\u003Cdiv class=\"language-java\" data-ext=\"java\" data-code=\"public%20interface%20UserMapper%20extends%20BaseMapper%3CUser%3E%20%7B%0A%7D%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-java\">\u003Cspan class=\"token keyword\">public\u003C\u002Fspan> \u003Cspan class=\"token keyword\">interface\u003C\u002Fspan> \u003Cspan class=\"token class-name\">UserMapper\u003C\u002Fspan> \u003Cspan class=\"token keyword\">extends\u003C\u002Fspan> \u003Cspan class=\"token class-name\">BaseMapper\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token class-name\">User\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">{\u003C\u002Fspan>\n\u003Cspan class=\"token punctuation\">}\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>然后，注入 Mapper :\u003C\u002Fp>\n\u003Cdiv class=\"language-java\" data-ext=\"java\" data-code=\"%40Autowired%0Aprivate%20UserMapper%20userMapper%3B%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-java\">\u003Cspan class=\"token annotation punctuation\">@Autowired\u003C\u002Fspan>\n\u003Cspan class=\"token keyword\">private\u003C\u002Fspan> \u003Cspan class=\"token class-name\">UserMapper\u003C\u002Fspan> userMapper\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>\u003Ccode>BaseMapper\u003C\u002Fcode> 提供的新增方法仅一个 \u003Ccode>insert()\u003C\u002Fcode> 方法：\u003C\u002Fp>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167220330351372-ApDw.jpg\" loading=\"lazy\">\u003C\u002Fdiv>\n\u003C\u002Fp>\n\u003Cp>我们通过它测试一下添加数据，并获取主键 ID :\u003C\u002Fp>\n\u003Cdiv class=\"language-dockerfile\" data-ext=\"dockerfile\" data-code=\"User%20user%20%3D%20new%20User()%3B%0Auser.setName(%22%E5%BC%A0%E4%B8%89%22)%3B%0Auser.setAge(30)%3B%0Auser.setGender(1)%3B%0A%0AuserMapper.insert(user)%3B%0A%0A%2F%2F%20%E8%8E%B7%E5%8F%96%E6%8F%92%E5%85%A5%E6%95%B0%E6%8D%AE%E7%9A%84%E4%B8%BB%E9%94%AE%20ID%0ALong%20id%20%3D%20user.getId()%3B%0A%0ASystem.out.println(%22id%3A%22%20%2B%20id)%3B%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-dockerfile\">\u003Cspan class=\"token instruction\">\u003Cspan class=\"token keyword\">User\u003C\u002Fspan> user = new User();\u003C\u002Fspan>\nuser.setName(\"张三\");\nuser.setAge(30);\nuser.setGender(1);\n\nuserMapper.insert(user);\n\n\u002F\u002F 获取插入数据的主键 ID\nLong id = user.getId();\n\nSystem.out.println(\"id:\" + id);\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>怎么样，是不是非常简单呢！\u003C\u002Fp>\n\u003Ch3 id=\"toc-7\">Service 层\u003C\u002Fh3>\n\u003Cp>Mybatis Plus 同样也封装了通用的 Service 层 CRUD 操作，并且提供了更丰富的方法。接下来，我们上手看 Service 层的代码结构，如下图：\u003C\u002Fp>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167204808139593-dWMf.jpg\" loading=\"lazy\" title=\"定义 Service 层\" alt=\"定义 Service 层\">\u003C\u002Fdiv>\u003Cspan class=\"image-caption\">定义 Service 层\u003C\u002Fspan>\n\u003C\u002Fp>\n\u003Cp>先定义 \u003Ccode>UserService\u003C\u002Fcode> 接口 ，让其继承自 \u003Ccode>IService\u003C\u002Fcode>:\u003C\u002Fp>\n\u003Cdiv class=\"language-java\" data-ext=\"java\" data-code=\"public%20interface%20UserService%20extends%20IService%3CUser%3E%20%7B%0A%7D%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-java\">\u003Cspan class=\"token keyword\">public\u003C\u002Fspan> \u003Cspan class=\"token keyword\">interface\u003C\u002Fspan> \u003Cspan class=\"token class-name\">UserService\u003C\u002Fspan> \u003Cspan class=\"token keyword\">extends\u003C\u002Fspan> \u003Cspan class=\"token class-name\">IService\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token class-name\">User\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">{\u003C\u002Fspan>\n\u003Cspan class=\"token punctuation\">}\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>再定义实现类 \u003Ccode>UserServiceImpl\u003C\u002Fcode>，让其继承自 \u003Ccode>ServiceImpl\u003C\u002Fcode>, 同时实现 \u003Ccode>UserService\u003C\u002Fcode> 接口，这样就可以让 \u003Ccode>UserService\u003C\u002Fcode> 拥有了基础通用的 CRUD 功能，当然，实际开发中，业务会更加复杂，就需要向 \u003Ccode>IService\u003C\u002Fcode> 接口自定义方法并实现:\u003C\u002Fp>\n\u003Cdiv class=\"language-java\" data-ext=\"java\" data-code=\"%40Service%0Apublic%20class%20UserServiceImpl%20extends%20ServiceImpl%3CUserMapper%2C%20User%3E%20implements%20UserService%20%7B%0A%7D%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-java\">\u003Cspan class=\"token annotation punctuation\">@Service\u003C\u002Fspan>\n\u003Cspan class=\"token keyword\">public\u003C\u002Fspan> \u003Cspan class=\"token keyword\">class\u003C\u002Fspan> \u003Cspan class=\"token class-name\">UserServiceImpl\u003C\u002Fspan> \u003Cspan class=\"token keyword\">extends\u003C\u002Fspan> \u003Cspan class=\"token class-name\">ServiceImpl\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token class-name\">UserMapper\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token class-name\">User\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> \u003Cspan class=\"token keyword\">implements\u003C\u002Fspan> \u003Cspan class=\"token class-name\">UserService\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">{\u003C\u002Fspan>\n\u003Cspan class=\"token punctuation\">}\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>注入 \u003Ccode>UserService\u003C\u002Fcode> :\u003C\u002Fp>\n\u003Cdiv class=\"language-java\" data-ext=\"java\" data-code=\"%40Autowired%0Aprivate%20UserService%20userService%3B%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-java\">\u003Cspan class=\"token annotation punctuation\">@Autowired\u003C\u002Fspan>\n\u003Cspan class=\"token keyword\">private\u003C\u002Fspan> \u003Cspan class=\"token class-name\">UserService\u003C\u002Fspan> userService\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>与 Mapper 层不同的是，Service 层的新增方法均以 \u003Ccode>save\u003C\u002Fcode> 开头，并且功能更丰富，来看看都提供了哪些方法：\u003C\u002Fp>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167204984846713-tDOT.jpg\" loading=\"lazy\" title=\"新增数据共有 6 个方法\" alt=\"新增数据共有 6 个方法\">\u003C\u002Fdiv>\u003Cspan class=\"image-caption\">新增数据共有 6 个方法\u003C\u002Fspan>\n\u003C\u002Fp>\n\u003Cp>简单解释下每个方法的作用，以作了解：\u003C\u002Fp>\n\u003Cdiv class=\"language-java\" data-ext=\"java\" data-code=\"%2F%2F%20%E6%96%B0%E5%A2%9E%E6%95%B0%E6%8D%AE%0Asava(T)%20%3A%20boolean%0A%2F%2F%20%E4%BC%AA%E6%89%B9%E9%87%8F%E6%8F%92%E5%85%A5%EF%BC%8C%E5%AE%9E%E9%99%85%E4%B8%8A%E6%98%AF%E9%80%9A%E8%BF%87%20for%20%E5%BE%AA%E7%8E%AF%E4%B8%80%E6%9D%A1%E4%B8%80%E6%9D%A1%E7%9A%84%E6%8F%92%E5%85%A5%0AsavaBatch(Collection%3CT%3E)%20%3A%20boolean%0A%2F%2F%20%E4%BC%AA%E6%89%B9%E9%87%8F%E6%8F%92%E5%85%A5%EF%BC%8Cint%20%E8%A1%A8%E7%A4%BA%E6%89%B9%E9%87%8F%E6%8F%90%E4%BA%A4%E6%95%B0%EF%BC%8C%E9%BB%98%E8%AE%A4%E4%B8%BA%201000%0AsavaBatch(Collection%3CT%3E%2C%20int)%20%3A%20boolean%0A%2F%2F%20%E6%96%B0%E5%A2%9E%E6%88%96%E6%9B%B4%E6%96%B0(%E5%8D%95%E6%9D%A1%E6%95%B0%E6%8D%AE)%0AsaveOrUpdate(T)%20%3A%20boolean%0A%2F%2F%20%E6%89%B9%E9%87%8F%E6%96%B0%E5%A2%9E%E6%88%96%E6%9B%B4%E6%96%B0%0AsaveOrUpdateBatch(Collection%3CT%3E)%20%3A%20boolean%0A%2F%2F%20%E6%89%B9%E9%87%8F%E6%96%B0%E5%A2%9E%E6%88%96%E6%9B%B4%E6%96%B0(%E5%8F%AF%E6%8C%87%E5%AE%9A%E6%89%B9%E9%87%8F%E6%8F%90%E4%BA%A4%E6%95%B0)%0AsaveOrUpdateBatch(Collection%3CT%3E%2C%20int)%20%3A%20boolean%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-java\">\u003Cspan class=\"token comment\">\u002F\u002F 新增数据\u003C\u002Fspan>\n\u003Cspan class=\"token function\">sava\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token class-name\">T\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token operator\">:\u003C\u002Fspan> \u003Cspan class=\"token keyword\">boolean\u003C\u002Fspan>\n\u003Cspan class=\"token comment\">\u002F\u002F 伪批量插入，实际上是通过 for 循环一条一条的插入\u003C\u002Fspan>\n\u003Cspan class=\"token function\">savaBatch\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token class-name\">Collection\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token class-name\">T\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token operator\">:\u003C\u002Fspan> \u003Cspan class=\"token keyword\">boolean\u003C\u002Fspan>\n\u003Cspan class=\"token comment\">\u002F\u002F 伪批量插入，int 表示批量提交数，默认为 1000\u003C\u002Fspan>\n\u003Cspan class=\"token function\">savaBatch\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token class-name\">Collection\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token class-name\">T\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token keyword\">int\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token operator\">:\u003C\u002Fspan> \u003Cspan class=\"token keyword\">boolean\u003C\u002Fspan>\n\u003Cspan class=\"token comment\">\u002F\u002F 新增或更新(单条数据)\u003C\u002Fspan>\n\u003Cspan class=\"token function\">saveOrUpdate\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token class-name\">T\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token operator\">:\u003C\u002Fspan> \u003Cspan class=\"token keyword\">boolean\u003C\u002Fspan>\n\u003Cspan class=\"token comment\">\u002F\u002F 批量新增或更新\u003C\u002Fspan>\n\u003Cspan class=\"token function\">saveOrUpdateBatch\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token class-name\">Collection\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token class-name\">T\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token operator\">:\u003C\u002Fspan> \u003Cspan class=\"token keyword\">boolean\u003C\u002Fspan>\n\u003Cspan class=\"token comment\">\u002F\u002F 批量新增或更新(可指定批量提交数)\u003C\u002Fspan>\n\u003Cspan class=\"token function\">saveOrUpdateBatch\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token class-name\">Collection\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token class-name\">T\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token keyword\">int\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token operator\">:\u003C\u002Fspan> \u003Cspan class=\"token keyword\">boolean\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>大致看完后，上手测试一下。\u003C\u002Fp>\n\u003Ch4 id=\"toc-8\">sava(T)\u003C\u002Fh4>\n\u003Cp>\u003Cstrong>简单的新增数据\u003C\u002Fstrong>，示例代码如下：\u003C\u002Fp>\n\u003Cdiv class=\"language-sql\" data-ext=\"sql\" data-code=\"%2F%2F%20%E6%96%B0%E5%A2%9E%E6%95%B0%E6%8D%AE%0A%2F%2F%20%E5%AE%9E%E9%99%85%E6%89%A7%E8%A1%8C%20SQL%20%3A%20INSERT%20INTO%20user%20(%20name%2C%20age%2C%20gender%20)%20VALUES%20(%20'%E5%BC%A0%E4%B8%89%20111'%2C%2030%2C%201%20)%0AUser%20user%20%3D%20new%20User()%3B%0Auser.setName(%22%E5%BC%A0%E4%B8%89%20111%22)%3B%0Auser.setAge(30)%3B%0Auser.setGender(1)%3B%0A%0Aboolean%20isSuccess%20%3D%20userService.save(user)%3B%0A%0A%2F%2F%20%E8%BF%94%E5%9B%9E%E4%B8%BB%E9%94%AEID%0ALong%20id%20%3D%20user.getId()%3B%0ASystem.out.println(%22isSuccess%3A%22%20%2B%20isSuccess)%3B%0ASystem.out.println(%22%E4%B8%BB%E9%94%AE%20ID%3A%20%22%20%2B%20id)%3B%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-sql\">\u003Cspan class=\"token comment\">\u002F\u002F 新增数据\u003C\u002Fspan>\n\u003Cspan class=\"token comment\">\u002F\u002F 实际执行 SQL : INSERT INTO user ( name, age, gender ) VALUES ( '张三111', 30, 1 )\u003C\u002Fspan>\n\u003Cspan class=\"token keyword\">User\u003C\u002Fspan> \u003Cspan class=\"token keyword\">user\u003C\u002Fspan> \u003Cspan class=\"token operator\">=\u003C\u002Fspan> new \u003Cspan class=\"token keyword\">User\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token keyword\">user\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>setName\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token string\">\"张三111\"\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token keyword\">user\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>setAge\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token number\">30\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token keyword\">user\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>setGender\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token number\">1\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\n\u003Cspan class=\"token keyword\">boolean\u003C\u002Fspan> isSuccess \u003Cspan class=\"token operator\">=\u003C\u002Fspan> userService\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token keyword\">save\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token keyword\">user\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\n\u003Cspan class=\"token comment\">\u002F\u002F 返回主键ID\u003C\u002Fspan>\nLong id \u003Cspan class=\"token operator\">=\u003C\u002Fspan> \u003Cspan class=\"token keyword\">user\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>getId\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\nSystem\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token keyword\">out\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>println\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token string\">\"isSuccess:\"\u003C\u002Fspan> \u003Cspan class=\"token operator\">+\u003C\u002Fspan> isSuccess\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\nSystem\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token keyword\">out\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>println\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token string\">\"主键 ID: \"\u003C\u002Fspan> \u003Cspan class=\"token operator\">+\u003C\u002Fspan> id\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Ch4 id=\"toc-9\">savaBatch(Collection\u003CT>)\u003C\u002Fh4>\n\u003Cp>\u003Cstrong>伪批量插入\u003C\u002Fstrong>，注意，命名虽然包含了批量的意思，但这不是真的批量插入，不信的话，我们来实际测试一下：\u003C\u002Fp>\n\u003Cdiv class=\"language-dockerfile\" data-ext=\"dockerfile\" data-code=\"%2F%2F%20%E6%89%B9%E9%87%8F%E6%8F%92%E5%85%A5%0AList%3CUser%3E%20users%20%3D%20new%20ArrayList%3C%3E()%3B%0Afor%20(int%20i%20%3D%200%3B%20i%20%3C%205%3B%20i%2B%2B)%20%7B%0A%20%20%20%20User%20user%20%3D%20new%20User()%3B%0A%20%20%20%20user.setName(%22%E5%BC%A0%E4%B8%89%22%20%2B%20i)%3B%0A%20%20%20%20user.setAge(i)%3B%0A%20%20%20%20user.setGender(1)%3B%0A%20%20%20%20users.add(user)%3B%0A%7D%0Aboolean%20isSuccess%20%3D%20userService.saveBatch(users)%3B%0ASystem.out.println(%22isSuccess%3A%22%20%2B%20isSuccess)%3B%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-dockerfile\">\u002F\u002F 批量插入\nList<User> users = new ArrayList<>();\nfor (int i = 0; i < 5; i++) {\n    \u003Cspan class=\"token instruction\">\u003Cspan class=\"token keyword\">User\u003C\u002Fspan> user = new User();\u003C\u002Fspan>\n    user.setName(\"张三\" + i);\n    user.setAge(i);\n    user.setGender(1);\n    users.add(user);\n}\nboolean isSuccess = userService.saveBatch(users);\nSystem.out.println(\"isSuccess:\" + isSuccess);\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>执行代码，实际执行的 SQL 如下：\u003C\u002Fp>\n\u003Cblockquote>\n\u003Cp>TIP : 如何打印实际执行的 SQL, 可参考之前小节的 《Mybatis Plus 打印 SQL 语句（包含执行耗时）》\u003Cspan>\u003Csvg xmlns=\"http:\u002F\u002Fwww.w3.org\u002F2000\u002Fsvg\" style=\"color: #aaa; margin-left: 3px;\" aria-hidden=\"true\" focusable=\"false\" x=\"0px\" y=\"0px\" viewBox=\"0 0 100 100\" width=\"15\" height=\"15\" class=\"icon outbound\">\u003Cpath fill=\"currentColor\" d=\"M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z\">\u003C\u002Fpath> \u003Cpolygon fill=\"currentColor\" points=\"45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9\">\u003C\u002Fpolygon>\u003C\u002Fsvg> \u003Cspan class=\"sr-only\">\u003C\u002Fspan>\u003C\u002Fspan>。\u003C\u002Fp>\n\u003C\u002Fblockquote>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167211863047181-DEdJ.jpg\" loading=\"lazy\" title=\"批量插入输入 SQL 打印\" alt=\"批量插入输入 SQL 打印\">\u003C\u002Fdiv>\u003Cspan class=\"image-caption\">批量插入输入 SQL 打印\u003C\u002Fspan>\n\u003C\u002Fp>\n\u003Cp>可以看到，并不是 \u003Ccode>insert into user (xxx) values (xxx),(xxx),(xxx)\u003C\u002Fcode> 这种批量形式，还是一条一条插入的。\u003C\u002Fp>\n\u003Ch5 id=\"toc-10\">批量新增源码分析\u003C\u002Fh5>\n\u003Cp>我们来看下源码, 内部的\u003Ccode>saveBatch()\u003C\u002Fcode> 方法默认的批量提交阀值参数，数值为 1000， 即达到 1000 条批量提交一次，继续点进去看：：\u003C\u002Fp>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167212963055320-ODNh.jpg\" loading=\"lazy\">\u003C\u002Fdiv>\n\u003C\u002Fp>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167211902799533.jpg\" loading=\"lazy\" title=\"源码分析\" alt=\"源码分析\">\u003C\u002Fdiv>\u003Cspan class=\"image-caption\">源码分析\u003C\u002Fspan>\n\u003C\u002Fp>\n\u003Cdiv class=\"language-java\" data-ext=\"java\" data-code=\"public%20boolean%20saveBatch(Collection%3CT%3E%20entityList%2C%20int%20batchSize)%20%7B%0A%20%20%20%20%20%20%20%20%2F%2F%20%E8%8E%B7%E5%8F%96%E9%A2%84%E7%BC%96%E8%AF%91%E7%9A%84%E6%8F%92%E5%85%A5%20SQL%0A%20%20%20%20%20%20%20%20String%20sqlStatement%20%3D%20this.getSqlStatement(SqlMethod.INSERT_ONE)%3B%0A%20%20%20%20%20%20%20%20%2F%2F%20for%20%E5%BE%AA%E7%8E%AF%E6%89%A7%E8%A1%8C%20insert%0A%20%20%20%20%20%20%20%20return%20this.executeBatch(entityList%2C%20batchSize%2C%20(sqlSession%2C%20entity)%20-%3E%20%7B%0A%20%20%20%20%20%20%20%20%20%20%20%20sqlSession.insert(sqlStatement%2C%20entity)%3B%0A%20%20%20%20%20%20%20%20%7D)%3B%0A%20%20%20%20%7D%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-java\">\u003Cspan class=\"token keyword\">public\u003C\u002Fspan> \u003Cspan class=\"token keyword\">boolean\u003C\u002Fspan> \u003Cspan class=\"token function\">saveBatch\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token class-name\">Collection\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token class-name\">T\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> entityList\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token keyword\">int\u003C\u002Fspan> batchSize\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">{\u003C\u002Fspan>\n        \u003Cspan class=\"token comment\">\u002F\u002F 获取预编译的插入 SQL\u003C\u002Fspan>\n        \u003Cspan class=\"token class-name\">String\u003C\u002Fspan> sqlStatement \u003Cspan class=\"token operator\">=\u003C\u002Fspan> \u003Cspan class=\"token keyword\">this\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">getSqlStatement\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token class-name\">SqlMethod\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token constant\">INSERT_ONE\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n        \u003Cspan class=\"token comment\">\u002F\u002F for 循环执行 insert\u003C\u002Fspan>\n        \u003Cspan class=\"token keyword\">return\u003C\u002Fspan> \u003Cspan class=\"token keyword\">this\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">executeBatch\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>entityList\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> batchSize\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>sqlSession\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> entity\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token operator\">->\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">{\u003C\u002Fspan>\n            sqlSession\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">insert\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>sqlStatement\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> entity\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n        \u003Cspan class=\"token punctuation\">}\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n    \u003Cspan class=\"token punctuation\">}\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>再看下 \u003Ccode>SqlMethod.INSERT_ONE\u003C\u002Fcode> 这个枚举，描述信息为\u003Cem>插入一条数据\u003C\u002Fem>：\u003C\u002Fp>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167213598609592-GcND.jpg\" loading=\"lazy\">\u003C\u002Fdiv>\n\u003C\u002Fp>\n\u003Cp>继续往 \u003Ccode>executeBatch()\u003C\u002Fcode> 方法里看，瞅瞅它这个批量到底是怎么处理的，具体每行代码的意思，都加了注释：\u003C\u002Fp>\n\u003Cdiv class=\"language-java\" data-ext=\"java\" data-code=\"%20%20%20%20public%20static%20%3CE%3E%20boolean%20executeBatch(Class%3C%3F%3E%20entityClass%2C%20Log%20log%2C%20Collection%3CE%3E%20list%2C%20int%20batchSize%2C%20BiConsumer%3CSqlSession%2C%20E%3E%20consumer)%20%7B%0A%20%20%20%20%09%2F%2F%20%E6%96%AD%E8%A8%80%E9%9C%80%E8%A6%81%E6%89%B9%E5%A4%84%E7%90%86%E6%95%B0%E6%8D%AE%E9%9B%86%E5%A4%A7%E5%B0%8F%E4%B8%8D%E7%AD%89%E4%BA%8E1%0A%20%20%20%20%20%20%20%20Assert.isFalse(batchSize%20%3C%201%2C%20%22batchSize%20must%20not%20be%20less%20than%20one%22%2C%20new%20Object%5B0%5D)%3B%0A%20%20%20%20%20%20%20%20%2F%2F%20%E5%88%A4%E7%A9%BA%E6%95%B0%E6%8D%AE%E9%9B%86%EF%BC%8C%E8%8B%A5%E4%B8%8D%E4%B8%BA%E7%A9%BA%EF%BC%8C%E5%88%99%E5%BC%80%E5%A7%8B%E6%89%A7%E8%A1%8C%E6%89%B9%E9%87%8F%E5%A4%84%E7%90%86%0A%20%20%20%20%20%20%20%20return%20!CollectionUtils.isEmpty(list)%20%26%26%20executeBatch(entityClass%2C%20log%2C%20(sqlSession)%20-%3E%20%7B%0A%20%20%20%20%20%20%20%20%09%0A%20%20%20%20%20%20%20%20%20%20%20%20int%20size%20%3D%20list.size()%3B%0A%20%20%20%20%20%20%20%20%20%20%20%20%2F%2F%20%E5%B0%86%E6%89%B9%E5%A4%84%E7%90%86%E5%A4%A7%E5%B0%8F%E4%B8%8E%E4%BC%A0%E5%85%A5%E7%9A%84%E6%93%8D%E4%BD%9C%E9%9B%86%E5%90%88%E5%A4%A7%E5%B0%8F%E8%BF%9B%E8%A1%8C%E6%AF%94%E8%BE%83%EF%BC%8C%E5%8F%96%E6%9C%80%E5%B0%8F%E7%9A%84%E9%82%A3%E4%B8%AA%0A%20%20%20%20%20%20%20%20%20%20%20%20int%20idxLimit%20%3D%20Math.min(batchSize%2C%20size)%3B%0A%20%20%20%20%20%20%20%20%20%20%20%20int%20i%20%3D%201%3B%0A%20%20%20%20%20%20%20%20%20%20%20%20%2F%2F%20%E8%BF%AD%E4%BB%A3%E5%99%A8%E5%BE%AA%E7%8E%AF%0A%20%20%20%20%20%20%20%20%20%20%20%20for(Iterator%20var7%20%3D%20list.iterator()%3B%20var7.hasNext()%3B%20%2B%2Bi)%20%7B%0A%20%20%20%20%20%20%20%20%20%20%20%20%09%2F%2F%20%E8%8E%B7%E5%8F%96%E5%BD%93%E5%89%8D%E9%9C%80%E8%A6%81%E6%89%A7%E8%A1%8C%E7%9A%84%E6%95%B0%E6%8D%AE%E5%BA%93%E6%93%8D%E4%BD%9C%0A%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20E%20element%20%3D%20var7.next()%3B%0A%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%2F%2F%20%E5%9B%9E%E8%B0%83%20sqlSession.insert()%20%E6%96%B9%E6%B3%95%0A%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20consumer.accept(sqlSession%2C%20element)%3B%0A%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%2F%2F%20%E5%88%A4%E6%96%AD%E6%98%AF%E5%90%A6%E8%BE%BE%E5%88%B0%E9%9C%80%E8%A6%81%E6%89%B9%E5%A4%84%E7%90%86%E7%9A%84%E9%98%80%E5%80%BC%0A%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20if%20(i%20%3D%3D%20idxLimit)%20%7B%0A%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%09%2F%2F%20%E5%BC%80%E5%A7%8B%E6%89%B9%E5%A4%84%E7%90%86%EF%BC%8C%E6%AD%A4%E6%96%B9%E6%B3%95%E6%89%A7%E8%A1%8C%E5%B9%B6%E6%B8%85%E9%99%A4%E7%BC%93%E5%AD%98%E5%9C%A8%20JDBC%20%E9%A9%B1%E5%8A%A8%E7%B1%BB%E4%B8%AD%E7%9A%84%E6%89%A7%E8%A1%8C%E8%AF%AD%E5%8F%A5%0A%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20sqlSession.flushStatements()%3B%0A%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20idxLimit%20%3D%20Math.min(idxLimit%20%2B%20batchSize%2C%20size)%3B%0A%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%7D%0A%20%20%20%20%20%20%20%20%20%20%20%20%7D%0A%20%20%20%20%20%20%20%20%7D)%3B%0A%20%20%20%20%7D%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-java\">    \u003Cspan class=\"token keyword\">public\u003C\u002Fspan> \u003Cspan class=\"token keyword\">static\u003C\u002Fspan> \u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token class-name\">E\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> \u003Cspan class=\"token keyword\">boolean\u003C\u002Fspan> \u003Cspan class=\"token function\">executeBatch\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token class-name\">Class\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token operator\">?\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> entityClass\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token class-name\">Log\u003C\u002Fspan> log\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token class-name\">Collection\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token class-name\">E\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> list\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token keyword\">int\u003C\u002Fspan> batchSize\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token class-name\">BiConsumer\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token class-name\">SqlSession\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token class-name\">E\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> consumer\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">{\u003C\u002Fspan>\n    \t\u003Cspan class=\"token comment\">\u002F\u002F 断言需要批处理数据集大小不等于1\u003C\u002Fspan>\n        \u003Cspan class=\"token class-name\">Assert\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">isFalse\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>batchSize \u003Cspan class=\"token operator\"><\u003C\u002Fspan> \u003Cspan class=\"token number\">1\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token string\">\"batchSize must not be less than one\"\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token keyword\">new\u003C\u002Fspan> \u003Cspan class=\"token class-name\">Object\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">[\u003C\u002Fspan>\u003Cspan class=\"token number\">0\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">]\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n        \u003Cspan class=\"token comment\">\u002F\u002F 判空数据集，若不为空，则开始执行批量处理\u003C\u002Fspan>\n        \u003Cspan class=\"token keyword\">return\u003C\u002Fspan> \u003Cspan class=\"token operator\">!\u003C\u002Fspan>\u003Cspan class=\"token class-name\">CollectionUtils\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">isEmpty\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>list\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token operator\">&&\u003C\u002Fspan> \u003Cspan class=\"token function\">executeBatch\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>entityClass\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> log\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>sqlSession\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token operator\">->\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">{\u003C\u002Fspan>\n        \t\n            \u003Cspan class=\"token keyword\">int\u003C\u002Fspan> size \u003Cspan class=\"token operator\">=\u003C\u002Fspan> list\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">size\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n            \u003Cspan class=\"token comment\">\u002F\u002F 将批处理大小与传入的操作集合大小进行比较，取最小的那个\u003C\u002Fspan>\n            \u003Cspan class=\"token keyword\">int\u003C\u002Fspan> idxLimit \u003Cspan class=\"token operator\">=\u003C\u002Fspan> \u003Cspan class=\"token class-name\">Math\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">min\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>batchSize\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> size\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n            \u003Cspan class=\"token keyword\">int\u003C\u002Fspan> i \u003Cspan class=\"token operator\">=\u003C\u002Fspan> \u003Cspan class=\"token number\">1\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n            \u003Cspan class=\"token comment\">\u002F\u002F 迭代器循环\u003C\u002Fspan>\n            \u003Cspan class=\"token keyword\">for\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token class-name\">Iterator\u003C\u002Fspan> var7 \u003Cspan class=\"token operator\">=\u003C\u002Fspan> list\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">iterator\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan> var7\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">hasNext\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan> \u003Cspan class=\"token operator\">++\u003C\u002Fspan>i\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">{\u003C\u002Fspan>\n            \t\u003Cspan class=\"token comment\">\u002F\u002F 获取当前需要执行的数据库操作\u003C\u002Fspan>\n                \u003Cspan class=\"token class-name\">E\u003C\u002Fspan> element \u003Cspan class=\"token operator\">=\u003C\u002Fspan> var7\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">next\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n                \u003Cspan class=\"token comment\">\u002F\u002F 回调 sqlSession.insert() 方法\u003C\u002Fspan>\n                consumer\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">accept\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>sqlSession\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> element\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n                \u003Cspan class=\"token comment\">\u002F\u002F 判断是否达到需要批处理的阀值\u003C\u002Fspan>\n                \u003Cspan class=\"token keyword\">if\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>i \u003Cspan class=\"token operator\">==\u003C\u002Fspan> idxLimit\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">{\u003C\u002Fspan>\n                \t\u003Cspan class=\"token comment\">\u002F\u002F 开始批处理，此方法执行并清除缓存在 JDBC 驱动类中的执行语句\u003C\u002Fspan>\n                    sqlSession\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">flushStatements\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n                    idxLimit \u003Cspan class=\"token operator\">=\u003C\u002Fspan> \u003Cspan class=\"token class-name\">Math\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">min\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>idxLimit \u003Cspan class=\"token operator\">+\u003C\u002Fspan> batchSize\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> size\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n                \u003Cspan class=\"token punctuation\">}\u003C\u002Fspan>\n            \u003Cspan class=\"token punctuation\">}\u003C\u002Fspan>\n        \u003Cspan class=\"token punctuation\">}\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n    \u003Cspan class=\"token punctuation\">}\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>看完就明白了，相比较自己手动 \u003Ccode>for\u003C\u002Fcode> 循环执行插入，Mybatis Plus 这个伪批量插入性能会更好些，内部会将每次的插入语句缓存起来，等到达到 1000 条的时候，才会统一推给数据库，虽然最终在数据库那边还是一条一条的执行 INSERT，但还是在和数据库交互的 IO 上做了优化。\u003C\u002Fp>\n\u003Ch4 id=\"toc-11\">savaBatch(Collection\u003CT>, int)\u003C\u002Fh4>\n\u003Cp>多了个 \u003Ccode>batchSize\u003C\u002Fcode> 参数，可以手动指定批处理的大小，即多少 SQL 操作执行一次，默认为 1000。\u003C\u002Fp>\n\u003Ch4 id=\"toc-12\">saveOrUpdate(T)\u003C\u002Fh4>\n\u003Cp>\u003Cstrong>保存或者更新\u003C\u002Fstrong>。即当你需要执行的数据，数据库中不存在时，就执行插入操作：\u003C\u002Fp>\n\u003Cdiv class=\"language-sql\" data-ext=\"sql\" data-code=\"%2F%2F%20%E5%AE%9E%E9%99%85%E6%89%A7%E8%A1%8C%20SQL%20%3A%20INSERT%20INTO%20user%20(%20name%2C%20age%2C%20gender%20)%20VALUES%20(%20'%E5%B0%8F%E5%BC%A0%E4%B8%89'%2C%2060%2C%201%20)%0AUser%20user%20%3D%20new%20User()%3B%0Auser.setName(%22%E5%B0%8F%E5%BC%A0%E4%B8%89%22)%3B%0Auser.setAge(60)%3B%0Auser.setGender(1)%3B%0AuserService.saveOrUpdate(user)%3B%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-sql\">\u003Cspan class=\"token comment\">\u002F\u002F 实际执行 SQL : INSERT INTO user ( name, age, gender ) VALUES ( '张小三', 60, 1 )\u003C\u002Fspan>\n\u003Cspan class=\"token keyword\">User\u003C\u002Fspan> \u003Cspan class=\"token keyword\">user\u003C\u002Fspan> \u003Cspan class=\"token operator\">=\u003C\u002Fspan> new \u003Cspan class=\"token keyword\">User\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token keyword\">user\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>setName\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token string\">\"张小三\"\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token keyword\">user\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>setAge\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token number\">60\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token keyword\">user\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>setGender\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token number\">1\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\nuserService\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>saveOrUpdate\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token keyword\">user\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>当你需要执行的数据，数据库中已存在时，就执行更新操作。框架是如何判断该记录是否存在呢？ 如设置了主键 ID，因为主键 ID 必须是唯一的，Mybatis Plus 会先执行查询操作，判断数据是否存在，存在即执行更新，否则，执行插入操作：\u003C\u002Fp>\n\u003Cdiv class=\"language-dockerfile\" data-ext=\"dockerfile\" data-code=\"User%20user%20%3D%20new%20User()%3B%0A%2F%2F%20%E8%AE%BE%E7%BD%AE%E4%BA%86%E4%B8%BB%E9%94%AE%E5%AD%97%E6%AE%B5%0Auser.setId(21L)%3B%0Auser.setName(%22%E5%B0%8F%E5%BC%A0%E4%B8%89%22)%3B%0Auser.setAge(60)%3B%0Auser.setGender(1)%3B%0AuserService.saveOrUpdate(user)%3B%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-dockerfile\">\u003Cspan class=\"token instruction\">\u003Cspan class=\"token keyword\">User\u003C\u002Fspan> user = new User();\u003C\u002Fspan>\n\u002F\u002F 设置了主键字段\nuser.setId(21L);\nuser.setName(\"张小三\");\nuser.setAge(60);\nuser.setGender(1);\nuserService.saveOrUpdate(user);\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>具体执行 SQL 如下：\u003C\u002Fp>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167212563888187-JSqc.jpg\" loading=\"lazy\">\u003C\u002Fdiv>\n\u003C\u002Fp>\n\u003Ch4 id=\"toc-13\">saveOrUpdateBatch(Collection\u003CT>)\u003C\u002Fh4>\n\u003Cp>批量保存或者更新，示例代码如下：\u003C\u002Fp>\n\u003Cdiv class=\"language-dockerfile\" data-ext=\"dockerfile\" data-code=\"List%3CUser%3E%20users%20%3D%20new%20ArrayList%3C%3E()%3B%0Afor%20(int%20i%20%3D%200%3B%20i%20%3C%205%3B%20i%2B%2B)%20%7B%0A%20%20%20%20User%20user%20%3D%20new%20User()%3B%0A%20%20%20%20user.setId(Long.valueOf(i))%3B%0A%20%20%20%20user.setName(%22%E5%BC%A0%E4%B8%89%22%20%2B%20i)%3B%0A%20%20%20%20user.setAge(i%2B1)%3B%0A%20%20%20%20user.setGender(1)%3B%0A%20%20%20%20users.add(user)%3B%0A%7D%0AuserService.saveOrUpdateBatch(users)%3B%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-dockerfile\">List<User> users = new ArrayList<>();\nfor (int i = 0; i < 5; i++) {\n    \u003Cspan class=\"token instruction\">\u003Cspan class=\"token keyword\">User\u003C\u002Fspan> user = new User();\u003C\u002Fspan>\n    user.setId(Long.valueOf(i));\n    user.setName(\"张三\" + i);\n    user.setAge(i+1);\n    user.setGender(1);\n    users.add(user);\n}\nuserService.saveOrUpdateBatch(users);\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Ch4 id=\"toc-14\">saveOrUpdateBatch(Collection\u003CT>, int)\u003C\u002Fh4>\n\u003Cp>批量保存或者更新（可手动指定批量大小），示例代码如下：\u003C\u002Fp>","\u003Cp>大家好。\u003C\u002Fp>\n\u003Cp>本小节中，我们将学习如何通过 Mybatis Plus 框架给数据库表新增数据，主要内容思维导图如下：\u003C\u002Fp>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167213988351654-zdcA.jpg\" loading=\"lazy\" title=\"Mybatis Plus 新增数据思维导图\" alt=\"Mybatis Plus 新增数据思维导图\">\u003Cspan class=\"image-caption\">Mybatis Plus 新增数据思维导图\u003C\u002Fspan>\n\u003C\u002Fp>\n\u003Ch2>表结构\u003C\u002Fh2>\n\u003Cp>为了演示新增数据，在前面小节中，我们已经定义好了一个用于测试的用户表， 执行脚本如下：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>DROP TABLE IF EXISTS t_user;\n\nCREATE TABLE `t_user` (\n  `id` bigint(20) UNSIGNED NOT NULL AUTO_INCREMENT COMMENT '主键ID',\n  `name` varchar(30) NOT NULL DEFAULT '' COMMENT '姓名',\n  `age` int(11) NULL DEFAULT NULL COMMENT '年龄',\n  `gender` tinyint(2) NOT NULL DEFAULT 0 COMMENT '性别，0：女 1：男',\n  PRIMARY KEY (`id`)\n) COMMENT = '用户表';\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Ch2>定义实体类\u003C\u002Fh2>\n\u003Cp>定义一个名为 \u003Ccode>User\u003C\u002Fcode> 实体类：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>@Data\n@TableName("t_user")\npublic class User {\n    \u002F**\n     * 主键 ID, @TableId 注解定义字段为表的主键，type 表示主键类型，IdType.AUTO 表示随着数据库 ID 自增\n     *\u002F\n    @TableId(type = IdType.AUTO)\n    private Long id;\n    \u002F**\n     * 姓名\n     *\u002F\n    private String name;\n    \u002F**\n     * 年龄\n     *\u002F\n    private Integer age;\n    \u002F**\n     * 性别\n     *\u002F\n    private Integer gender;\n}\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>讲解一下实体类中用到的注解：\u003C\u002Fp>\n\u003Ch3>@TableName 表名注解\u003C\u002Fh3>\n\u003Cp>作用：\u003Cstrong>标识实体类对应的表\u003C\u002Fstrong>。\u003C\u002Fp>\n\u003Cblockquote>\n\u003Cp>TIP ：\u003C\u002Fp>\n\u003Cul>\n\u003Cli>当实体类名称和实际表名一致时，如实体名为 \u003Ccode>User\u003C\u002Fcode>， 表名为 \u003Ccode>user\u003C\u002Fcode> ，可不用添加该注解，Mybatis Plus 会自动识别并映射到该表。\u003C\u002Fli>\n\u003Cli>当实体类名称和实际表名不一致时，如实体名为 \u003Ccode>User\u003C\u002Fcode>， 表名为 \u003Ccode>t_user\u003C\u002Fcode>，需手动添加该注解，并填写实际表名称。\u003C\u002Fli>\n\u003C\u002Ful>\n\u003C\u002Fblockquote>\n\u003Ch3>@TableId 主键注解\u003C\u002Fh3>\n\u003Cp>作用：\u003Cstrong>声明实体类中的主键对应的字段\u003C\u002Fstrong>。\u003C\u002Fp>\n\u003Ctable>\n\u003Cthead>\n\u003Ctr>\n\u003Cth align=\"left\">属性\u003C\u002Fth>\n\u003Cth align=\"left\">类型\u003C\u002Fth>\n\u003Cth align=\"left\">必须指定\u003C\u002Fth>\n\u003Cth align=\"left\">默认值\u003C\u002Fth>\n\u003Cth align=\"left\">描述\u003C\u002Fth>\n\u003C\u002Ftr>\n\u003C\u002Fthead>\n\u003Ctbody>\n\u003Ctr>\n\u003Ctd align=\"left\">value\u003C\u002Ftd>\n\u003Ctd align=\"left\">String\u003C\u002Ftd>\n\u003Ctd align=\"left\">否\u003C\u002Ftd>\n\u003Ctd align=\"left\">""\u003C\u002Ftd>\n\u003Ctd align=\"left\">主键字段名\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">type\u003C\u002Ftd>\n\u003Ctd align=\"left\">Enum\u003C\u002Ftd>\n\u003Ctd align=\"left\">否\u003C\u002Ftd>\n\u003Ctd align=\"left\">IdType.NONE\u003C\u002Ftd>\n\u003Ctd align=\"left\">指定主键类型\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003C\u002Ftbody>\n\u003C\u002Ftable>\n\u003Ch3>IdType 主键类型\u003C\u002Fh3>\n\u003Ctable>\n\u003Cthead>\n\u003Ctr>\n\u003Cth align=\"left\">值\u003C\u002Fth>\n\u003Cth align=\"left\">描述\u003C\u002Fth>\n\u003C\u002Ftr>\n\u003C\u002Fthead>\n\u003Ctbody>\n\u003Ctr>\n\u003Ctd align=\"left\">AUTO\u003C\u002Ftd>\n\u003Ctd align=\"left\">数据库 ID 自增\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">NONE\u003C\u002Ftd>\n\u003Ctd align=\"left\">无状态，该类型为未设置主键类型（默认）\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">INPUT\u003C\u002Ftd>\n\u003Ctd align=\"left\">插入数据前，需自行设置主键的值\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">ASSIGN_ID\u003C\u002Ftd>\n\u003Ctd align=\"left\">分配 ID(主键类型为 Number(Long 和 Integer)或 String)(since 3.3.0),使用接口\u003Ccode>IdentifierGenerator\u003C\u002Fcode>的方法\u003Ccode>nextId\u003C\u002Fcode>(默认实现类为\u003Ccode>DefaultIdentifierGenerator\u003C\u002Fcode>雪花算法)\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">ASSIGN_UUID\u003C\u002Ftd>\n\u003Ctd align=\"left\">分配 UUID,主键类型为 String(since 3.3.0),使用接口\u003Ccode>IdentifierGenerator\u003C\u002Fcode>的方法\u003Ccode>nextUUID\u003C\u002Fcode> (默认 default 方法)\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">~~ID_WORKER~~\u003C\u002Ftd>\n\u003Ctd align=\"left\">分布式全局唯一 ID 长整型类型 (推荐使用 \u003Ccode>ASSIGN_ID\u003C\u002Fcode>)\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">~~UUID~~\u003C\u002Ftd>\n\u003Ctd align=\"left\">32 位 UUID 字符串 (推荐使用 \u003Ccode>ASSIGN_UUID\u003C\u002Fcode>)\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">~~ID_WORKER_STR~~\u003C\u002Ftd>\n\u003Ctd align=\"left\">分布式全局唯一 ID 字符串类型 (推荐使用 \u003Ccode>ASSIGN_ID\u003C\u002Fcode>)\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003C\u002Ftbody>\n\u003C\u002Ftable>\n\u003Ch2>开始新增数据\u003C\u002Fh2>\n\u003Cp>测试表准备好后，我们准备开始演示新增数据。实际上，Mybatis Plus 对 Mapper 层和 Service 层都将常见的增删改查操作都封装好了，只需简单的继承，即可轻松搞定对数据的增删改查，本文重点讲解新增数据这块。\u003C\u002Fp>\n\u003Ch3>Mapper 层\u003C\u002Fh3>\n\u003Cp>定义一个 \u003Ccode>UserMapper\u003C\u002Fcode> , 让其继承 \u003Ccode>BaseMapper\u003C\u002Fcode> :\u003C\u002Fp>\n\u003Cpre>\u003Ccode>public interface UserMapper extends BaseMapper<User> {\n}\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>然后，注入 Mapper :\u003C\u002Fp>\n\u003Cpre>\u003Ccode>@Autowired\nprivate UserMapper userMapper;\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>\u003Ccode>BaseMapper\u003C\u002Fcode> 提供的新增方法仅一个 \u003Ccode>insert()\u003C\u002Fcode> 方法：\u003C\u002Fp>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167220330351372-ApDw.jpg\" loading=\"lazy\">\n\u003C\u002Fp>\n\u003Cp>我们通过它测试一下添加数据，并获取主键 ID :\u003C\u002Fp>\n\u003Cpre>\u003Ccode>User user = new User();\nuser.setName("张三");\nuser.setAge(30);\nuser.setGender(1);\n\nuserMapper.insert(user);\n\n\u002F\u002F 获取插入数据的主键 ID\nLong id = user.getId();\n\nSystem.out.println("id:" + id);\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>怎么样，是不是非常简单呢！\u003C\u002Fp>\n\u003Ch3>Service 层\u003C\u002Fh3>\n\u003Cp>Mybatis Plus 同样也封装了通用的 Service 层 CRUD 操作，并且提供了更丰富的方法。接下来，我们上手看 Service 层的代码结构，如下图：\u003C\u002Fp>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167204808139593-dWMf.jpg\" loading=\"lazy\" title=\"定义 Service 层\" alt=\"定义 Service 层\">\u003Cspan class=\"image-caption\">定义 Service 层\u003C\u002Fspan>\n\u003C\u002Fp>\n\u003Cp>先定义 \u003Ccode>UserService\u003C\u002Fcode> 接口 ，让其继承自 \u003Ccode>IService\u003C\u002Fcode>:\u003C\u002Fp>\n\u003Cpre>\u003Ccode>public interface UserService extends IService<User> {\n}\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>再定义实现类 \u003Ccode>UserServiceImpl\u003C\u002Fcode>，让其继承自 \u003Ccode>ServiceImpl\u003C\u002Fcode>, 同时实现 \u003Ccode>UserService\u003C\u002Fcode> 接口，这样就可以让 \u003Ccode>UserService\u003C\u002Fcode> 拥有了基础通用的 CRUD 功能，当然，实际开发中，业务会更加复杂，就需要向 \u003Ccode>IService\u003C\u002Fcode> 接口自定义方法并实现:\u003C\u002Fp>\n\u003Cpre>\u003Ccode>@Service\npublic class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService {\n}\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>注入 \u003Ccode>UserService\u003C\u002Fcode> :\u003C\u002Fp>\n\u003Cpre>\u003Ccode>@Autowired\nprivate UserService userService;\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>与 Mapper 层不同的是，Service 层的新增方法均以 \u003Ccode>save\u003C\u002Fcode> 开头，并且功能更丰富，来看看都提供了哪些方法：\u003C\u002Fp>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167204984846713-tDOT.jpg\" loading=\"lazy\" title=\"新增数据共有 6 个方法\" alt=\"新增数据共有 6 个方法\">\u003Cspan class=\"image-caption\">新增数据共有 6 个方法\u003C\u002Fspan>\n\u003C\u002Fp>\n\u003Cp>简单解释下每个方法的作用，以作了解：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>\u002F\u002F 新增数据\nsava(T) : boolean\n\u002F\u002F 伪批量插入，实际上是通过 for 循环一条一条的插入\nsavaBatch(Collection<T>) : boolean\n\u002F\u002F 伪批量插入，int 表示批量提交数，默认为 1000\nsavaBatch(Collection<T>, int) : boolean\n\u002F\u002F 新增或更新(单条数据)\nsaveOrUpdate(T) : boolean\n\u002F\u002F 批量新增或更新\nsaveOrUpdateBatch(Collection<T>) : boolean\n\u002F\u002F 批量新增或更新(可指定批量提交数)\nsaveOrUpdateBatch(Collection<T>, int) : boolean\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>大致看完后，上手测试一下。\u003C\u002Fp>\n\u003Ch4>sava(T)\u003C\u002Fh4>\n\u003Cp>\u003Cstrong>简单的新增数据\u003C\u002Fstrong>，示例代码如下：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>\u002F\u002F 新增数据\n\u002F\u002F 实际执行 SQL : INSERT INTO user ( name, age, gender ) VALUES ( '张三111', 30, 1 )\nUser user = new User();\nuser.setName("张三111");\nuser.setAge(30);\nuser.setGender(1);\n\nboolean isSuccess = userService.save(user);\n\n\u002F\u002F 返回主键ID\nLong id = user.getId();\nSystem.out.println("isSuccess:" + isSuccess);\nSystem.out.println("主键 ID: " + id);\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Ch4>savaBatch(Collection\u003CT>)\u003C\u002Fh4>\n\u003Cp>\u003Cstrong>伪批量插入\u003C\u002Fstrong>，注意，命名虽然包含了批量的意思，但这不是真的批量插入，不信的话，我们来实际测试一下：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>\u002F\u002F 批量插入\nList<User> users = new ArrayList<>();\nfor (int i = 0; i < 5; i++) {\n    User user = new User();\n    user.setName("张三" + i);\n    user.setAge(i);\n    user.setGender(1);\n    users.add(user);\n}\nboolean isSuccess = userService.saveBatch(users);\nSystem.out.println("isSuccess:" + isSuccess);\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>执行代码，实际执行的 SQL 如下：\u003C\u002Fp>\n\u003Cblockquote>\n\u003Cp>TIP : 如何打印实际执行的 SQL, 可参考之前小节的 《Mybatis Plus 打印 SQL 语句（包含执行耗时）》\u003Cspan>\u003Csvg xmlns=\"http:\u002F\u002Fwww.w3.org\u002F2000\u002Fsvg\" style=\"color: #aaa; margin-left: 3px;\" aria-hidden=\"true\" focusable=\"false\" x=\"0px\" y=\"0px\" viewBox=\"0 0 100 100\" width=\"15\" height=\"15\" class=\"icon outbound\">\u003Cpath fill=\"currentColor\" d=\"M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z\">\u003C\u002Fpath> \u003Cpolygon fill=\"currentColor\" points=\"45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9\">\u003C\u002Fpolygon>\u003C\u002Fsvg> \u003Cspan class=\"sr-only\">\u003C\u002Fspan>\u003C\u002Fspan>。\u003C\u002Fp>\n\u003C\u002Fblockquote>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167211863047181-DEdJ.jpg\" loading=\"lazy\" title=\"批量插入输入 SQL 打印\" alt=\"批量插入输入 SQL 打印\">\u003Cspan class=\"image-caption\">批量插入输入 SQL 打印\u003C\u002Fspan>\n\u003C\u002Fp>\n\u003Cp>可以看到，并不是 \u003Ccode>insert into user (xxx) values (xxx),(xxx),(xxx)\u003C\u002Fcode> 这种批量形式，还是一条一条插入的。\u003C\u002Fp>\n\u003Ch5>批量新增源码分析\u003C\u002Fh5>\n\u003Cp>我们来看下源码, 内部的\u003Ccode>saveBatch()\u003C\u002Fcode> 方法默认的批量提交阀值参数，数值为 1000， 即达到 1000 条批量提交一次，继续点进去看：：\u003C\u002Fp>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167212963055320-ODNh.jpg\" loading=\"lazy\">\n\u003C\u002Fp>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167211902799533.jpg\" loading=\"lazy\" title=\"源码分析\" alt=\"源码分析\">\u003Cspan class=\"image-caption\">源码分析\u003C\u002Fspan>\n\u003C\u002Fp>\n\u003Cpre>\u003Ccode>public boolean saveBatch(Collection<T> entityList, int batchSize) {\n        \u002F\u002F 获取预编译的插入 SQL\n        String sqlStatement = this.getSqlStatement(SqlMethod.INSERT_ONE);\n        \u002F\u002F for 循环执行 insert\n        return this.executeBatch(entityList, batchSize, (sqlSession, entity) -> {\n            sqlSession.insert(sqlStatement, entity);\n        });\n    }\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>再看下 \u003Ccode>SqlMethod.INSERT_ONE\u003C\u002Fcode> 这个枚举，描述信息为\u003Cem>插入一条数据\u003C\u002Fem>：\u003C\u002Fp>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167213598609592-GcND.jpg\" loading=\"lazy\">\n\u003C\u002Fp>\n\u003Cp>继续往 \u003Ccode>executeBatch()\u003C\u002Fcode> 方法里看，瞅瞅它这个批量到底是怎么处理的，具体每行代码的意思，都加了注释：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>    public static <E> boolean executeBatch(Class<?> entityClass, Log log, Collection<E> list, int batchSize, BiConsumer<SqlSession, E> consumer) {\n    \t\u002F\u002F 断言需要批处理数据集大小不等于1\n        Assert.isFalse(batchSize < 1, "batchSize must not be less than one", new Object[0]);\n        \u002F\u002F 判空数据集，若不为空，则开始执行批量处理\n        return !CollectionUtils.isEmpty(list) && executeBatch(entityClass, log, (sqlSession) -> {\n        \t\n            int size = list.size();\n            \u002F\u002F 将批处理大小与传入的操作集合大小进行比较，取最小的那个\n            int idxLimit = Math.min(batchSize, size);\n            int i = 1;\n            \u002F\u002F 迭代器循环\n            for(Iterator var7 = list.iterator(); var7.hasNext(); ++i) {\n            \t\u002F\u002F 获取当前需要执行的数据库操作\n                E element = var7.next();\n                \u002F\u002F 回调 sqlSession.insert() 方法\n                consumer.accept(sqlSession, element);\n                \u002F\u002F 判断是否达到需要批处理的阀值\n                if (i == idxLimit) {\n                \t\u002F\u002F 开始批处理，此方法执行并清除缓存在 JDBC 驱动类中的执行语句\n                    sqlSession.flushStatements();\n                    idxLimit = Math.min(idxLimit + batchSize, size);\n                }\n            }\n        });\n    }\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>看完就明白了，相比较自己手动 \u003Ccode>for\u003C\u002Fcode> 循环执行插入，Mybatis Plus 这个伪批量插入性能会更好些，内部会将每次的插入语句缓存起来，等到达到 1000 条的时候，才会统一推给数据库，虽然最终在数据库那边还是一条一条的执行 INSERT，但还是在和数据库交互的 IO 上做了优化。\u003C\u002Fp>\n\u003Ch4>savaBatch(Collection\u003CT>, int)\u003C\u002Fh4>\n\u003Cp>多了个 \u003Ccode>batchSize\u003C\u002Fcode> 参数，可以手动指定批处理的大小，即多少 SQL 操作执行一次，默认为 1000。\u003C\u002Fp>\n\u003Ch4>saveOrUpdate(T)\u003C\u002Fh4>\n\u003Cp>\u003Cstrong>保存或者更新\u003C\u002Fstrong>。即当你需要执行的数据，数据库中不存在时，就执行插入操作：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>\u002F\u002F 实际执行 SQL : INSERT INTO user ( name, age, gender ) VALUES ( '张小三', 60, 1 )\nUser user = new User();\nuser.setName("张小三");\nuser.setAge(60);\nuser.setGender(1);\nuserService.saveOrUpdate(user);\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>当你需要执行的数据，数据库中已存在时，就执行更新操作。框架是如何判断该记录是否存在呢？ 如设置了主键 ID，因为主键 ID 必须是唯一的，Mybatis Plus 会先执行查询操作，判断数据是否存在，存在即执行更新，否则，执行插入操作：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>User user = new User();\n\u002F\u002F 设置了主键字段\nuser.setId(21L);\nuser.setName("张小三");\nuser.setAge(60);\nuser.setGender(1);\nuserService.saveOrUpdate(user);\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>具体执行 SQL 如下：\u003C\u002Fp>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167212563888187-JSqc.jpg\" loading=\"lazy\">\n\u003C\u002Fp>\n\u003Ch4>saveOrUpdateBatch(Collection\u003CT>)\u003C\u002Fh4>\n\u003Cp>批量保存或者更新，示例代码如下：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>List<User> users = new ArrayList<>();\nfor (int i = 0; i < 5; i++) {\n    User user = new User();\n    user.setId(Long.valueOf(i));\n    user.setName("张三" + i);\n    user.setAge(i+1);\n    user.setGender(1);\n    users.add(user);\n}\nuserService.saveOrUpdateBatch(users);\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Ch4>saveOrUpdateBatch(Collection\u003CT>, int)\u003C\u002Fh4>\n\u003Cp>批量保存或者更新（可手动指定批量大小），示例代码如下：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>List<User> users = new ArrayList<>();\nfor (int i = 0; i < 5; i++) {\n    User user = new User();\n    user.setId(Long.valueOf(i));\n    user.setName("张三" + i);\n    user.setAge(i+1);\n    user.setGender(1);\n    users.add(user);\n}\nuserService.saveOrUpdateBatch(users, 100);\n\u003C\u002Fcode>\u003C\u002Fpre>\n13:Tbb50,\u003Cp>大家好。\u003C\u002Fp>\n\u003Cp>本小节中，我们将学习如何通过 Mybatis Plus 框架给数据库表新增数据，主要内容思维导图如下：\u003C\u002Fp>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167213988351654-zdcA.jpg\" loading=\"lazy\" title=\"Mybatis Plus 新增数据思维导图\" alt=\"Mybatis Plus 新增数据思维导图\">\u003C\u002Fdiv>\u003Cspan class=\"image-caption\">Mybatis Plus 新增数据思维导图\u003C\u002Fspan>\n\u003C\u002Fp>\n\u003Ch2 id=\"toc-0\">表结构\u003C\u002Fh2>\n\u003Cp>为了演示新增数据，在前面小节中，我们已经定义好了一个用于测试的用户表， 执行脚本如下：\u003C\u002Fp>\n\u003Cdiv class=\"language-sql\" data-ext=\"sql\" data-code=\"DROP%20TABLE%20IF%20EXISTS%20t_user%3B%0A%0ACREATE%20TABLE%20%60t_user%60%20(%0A%20%20%60id%60%20bigint(20)%20UNSIGNED%20NOT%20NULL%20AUTO_INCREMENT%20COMMENT%20'%E4%B8%BB%E9%94%AEID'%2C%0A%20%20%60name%60%20varchar(30)%20NOT%20NULL%20DEFAULT%20''%20COMMENT%20'%E5%A7%93%E5%90%8D'%2C%0A%20%20%60age%60%20int(11)%20NULL%20DEFAULT%20NULL%20COMMENT%20'%E5%B9%B4%E9%BE%84'%2C%0A%20%20%60gender%60%20tinyint(2)%20NOT%20NULL%20DEFAULT%200%20COMMENT%20'%E6%80%A7%E5%88%AB%EF%BC%8C0%EF%BC%9A%E5%A5%B3%201%EF%BC%9A%E7%94%B7'%2C%0A%20%20PRIMARY%20KEY%20(%60id%60)%0A)%20COMMENT%20%3D%20'%E7%94%A8%E6%88%B7%E8%A1%A8'%3B%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-sql\">\u003Cspan class=\"token keyword\">DROP\u003C\u002Fspan> \u003Cspan class=\"token keyword\">TABLE\u003C\u002Fspan> \u003Cspan class=\"token keyword\">IF\u003C\u002Fspan> \u003Cspan class=\"token keyword\">EXISTS\u003C\u002Fspan> t_user\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\n\u003Cspan class=\"token keyword\">CREATE\u003C\u002Fspan> \u003Cspan class=\"token keyword\">TABLE\u003C\u002Fspan> \u003Cspan class=\"token identifier\">\u003Cspan class=\"token punctuation\">`\u003C\u002Fspan>t_user\u003Cspan class=\"token punctuation\">`\u003C\u002Fspan>\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\n  \u003Cspan class=\"token identifier\">\u003Cspan class=\"token punctuation\">`\u003C\u002Fspan>id\u003Cspan class=\"token punctuation\">`\u003C\u002Fspan>\u003C\u002Fspan> \u003Cspan class=\"token keyword\">bigint\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token number\">20\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token keyword\">UNSIGNED\u003C\u002Fspan> \u003Cspan class=\"token operator\">NOT\u003C\u002Fspan> \u003Cspan class=\"token boolean\">NULL\u003C\u002Fspan> \u003Cspan class=\"token keyword\">AUTO_INCREMENT\u003C\u002Fspan> \u003Cspan class=\"token keyword\">COMMENT\u003C\u002Fspan> \u003Cspan class=\"token string\">'主键ID'\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan>\n  \u003Cspan class=\"token identifier\">\u003Cspan class=\"token punctuation\">`\u003C\u002Fspan>name\u003Cspan class=\"token punctuation\">`\u003C\u002Fspan>\u003C\u002Fspan> \u003Cspan class=\"token keyword\">varchar\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token number\">30\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token operator\">NOT\u003C\u002Fspan> \u003Cspan class=\"token boolean\">NULL\u003C\u002Fspan> \u003Cspan class=\"token keyword\">DEFAULT\u003C\u002Fspan> \u003Cspan class=\"token string\">''\u003C\u002Fspan> \u003Cspan class=\"token keyword\">COMMENT\u003C\u002Fspan> \u003Cspan class=\"token string\">'姓名'\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan>\n  \u003Cspan class=\"token identifier\">\u003Cspan class=\"token punctuation\">`\u003C\u002Fspan>age\u003Cspan class=\"token punctuation\">`\u003C\u002Fspan>\u003C\u002Fspan> \u003Cspan class=\"token keyword\">int\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token number\">11\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token boolean\">NULL\u003C\u002Fspan> \u003Cspan class=\"token keyword\">DEFAULT\u003C\u002Fspan> \u003Cspan class=\"token boolean\">NULL\u003C\u002Fspan> \u003Cspan class=\"token keyword\">COMMENT\u003C\u002Fspan> \u003Cspan class=\"token string\">'年龄'\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan>\n  \u003Cspan class=\"token identifier\">\u003Cspan class=\"token punctuation\">`\u003C\u002Fspan>gender\u003Cspan class=\"token punctuation\">`\u003C\u002Fspan>\u003C\u002Fspan> \u003Cspan class=\"token keyword\">tinyint\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token number\">2\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token operator\">NOT\u003C\u002Fspan> \u003Cspan class=\"token boolean\">NULL\u003C\u002Fspan> \u003Cspan class=\"token keyword\">DEFAULT\u003C\u002Fspan> \u003Cspan class=\"token number\">0\u003C\u002Fspan> \u003Cspan class=\"token keyword\">COMMENT\u003C\u002Fspan> \u003Cspan class=\"token string\">'性别，0：女 1：男'\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan>\n  \u003Cspan class=\"token keyword\">PRIMARY\u003C\u002Fspan> \u003Cspan class=\"token keyword\">KEY\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token identifier\">\u003Cspan class=\"token punctuation\">`\u003C\u002Fspan>id\u003Cspan class=\"token punctuation\">`\u003C\u002Fspan>\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\n\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token keyword\">COMMENT\u003C\u002Fspan> \u003Cspan class=\"token operator\">=\u003C\u002Fspan> \u003Cspan class=\"token string\">'用户表'\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Ch2 id=\"toc-1\">定义实体类\u003C\u002Fh2>\n\u003Cp>定义一个名为 \u003Ccode>User\u003C\u002Fcode> 实体类：\u003C\u002Fp>\n\u003Cdiv class=\"language-java\" data-ext=\"java\" data-code=\"%40Data%0A%40TableName(%22t_user%22)%0Apublic%20class%20User%20%7B%0A%20%20%20%20%2F**%0A%20%20%20%20%20*%20%E4%B8%BB%E9%94%AE%20ID%2C%20%40TableId%20%E6%B3%A8%E8%A7%A3%E5%AE%9A%E4%B9%89%E5%AD%97%E6%AE%B5%E4%B8%BA%E8%A1%A8%E7%9A%84%E4%B8%BB%E9%94%AE%EF%BC%8Ctype%20%E8%A1%A8%E7%A4%BA%E4%B8%BB%E9%94%AE%E7%B1%BB%E5%9E%8B%EF%BC%8CIdType.AUTO%20%E8%A1%A8%E7%A4%BA%E9%9A%8F%E7%9D%80%E6%95%B0%E6%8D%AE%E5%BA%93%20ID%20%E8%87%AA%E5%A2%9E%0A%20%20%20%20%20*%2F%0A%20%20%20%20%40TableId(type%20%3D%20IdType.AUTO)%0A%20%20%20%20private%20Long%20id%3B%0A%20%20%20%20%2F**%0A%20%20%20%20%20*%20%E5%A7%93%E5%90%8D%0A%20%20%20%20%20*%2F%0A%20%20%20%20private%20String%20name%3B%0A%20%20%20%20%2F**%0A%20%20%20%20%20*%20%E5%B9%B4%E9%BE%84%0A%20%20%20%20%20*%2F%0A%20%20%20%20private%20Integer%20age%3B%0A%20%20%20%20%2F**%0A%20%20%20%20%20*%20%E6%80%A7%E5%88%AB%0A%20%20%20%20%20*%2F%0A%20%20%20%20private%20Integer%20gender%3B%0A%7D%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-java\">\u003Cspan class=\"token annotation punctuation\">@Data\u003C\u002Fspan>\n\u003Cspan class=\"token annotation punctuation\">@TableName\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token string\">\"t_user\"\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\n\u003Cspan class=\"token keyword\">public\u003C\u002Fspan> \u003Cspan class=\"token keyword\">class\u003C\u002Fspan> \u003Cspan class=\"token class-name\">User\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">{\u003C\u002Fspan>\n    \u003Cspan class=\"token comment\">\u002F**\n     * 主键 ID, @TableId 注解定义字段为表的主键，type 表示主键类型，IdType.AUTO 表示随着数据库 ID 自增\n     *\u002F\u003C\u002Fspan>\n    \u003Cspan class=\"token annotation punctuation\">@TableId\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>type \u003Cspan class=\"token operator\">=\u003C\u002Fspan> \u003Cspan class=\"token class-name\">IdType\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token constant\">AUTO\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\n    \u003Cspan class=\"token keyword\">private\u003C\u002Fspan> \u003Cspan class=\"token class-name\">Long\u003C\u002Fspan> id\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n    \u003Cspan class=\"token comment\">\u002F**\n     * 姓名\n     *\u002F\u003C\u002Fspan>\n    \u003Cspan class=\"token keyword\">private\u003C\u002Fspan> \u003Cspan class=\"token class-name\">String\u003C\u002Fspan> name\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n    \u003Cspan class=\"token comment\">\u002F**\n     * 年龄\n     *\u002F\u003C\u002Fspan>\n    \u003Cspan class=\"token keyword\">private\u003C\u002Fspan> \u003Cspan class=\"token class-name\">Integer\u003C\u002Fspan> age\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n    \u003Cspan class=\"token comment\">\u002F**\n     * 性别\n     *\u002F\u003C\u002Fspan>\n    \u003Cspan class=\"token keyword\">private\u003C\u002Fspan> \u003Cspan class=\"token class-name\">Integer\u003C\u002Fspan> gender\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token punctuation\">}\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>讲解一下实体类中用到的注解：\u003C\u002Fp>\n\u003Ch3 id=\"toc-2\">@TableName 表名注解\u003C\u002Fh3>\n\u003Cp>作用：\u003Cstrong>标识实体类对应的表\u003C\u002Fstrong>。\u003C\u002Fp>\n\u003Cblockquote>\n\u003Cp>TIP ：\u003C\u002Fp>\n\u003Cul>\n\u003Cli>当实体类名称和实际表名一致时，如实体名为 \u003Ccode>User\u003C\u002Fcode>， 表名为 \u003Ccode>user\u003C\u002Fcode> ，可不用添加该注解，Mybatis Plus 会自动识别并映射到该表。\u003C\u002Fli>\n\u003Cli>当实体类名称和实际表名不一致时，如实体名为 \u003Ccode>User\u003C\u002Fcode>， 表名为 \u003Ccode>t_user\u003C\u002Fcode>，需手动添加该注解，并填写实际表名称。\u003C\u002Fli>\n\u003C\u002Ful>\n\u003C\u002Fblockquote>\n\u003Ch3 id=\"toc-3\">@TableId 主键注解\u003C\u002Fh3>\n\u003Cp>作用：\u003Cstrong>声明实体类中的主键对应的字段\u003C\u002Fstrong>。\u003C\u002Fp>\n\u003Ctable>\n\u003Cthead>\n\u003Ctr>\n\u003Cth align=\"left\">属性\u003C\u002Fth>\n\u003Cth align=\"left\">类型\u003C\u002Fth>\n\u003Cth align=\"left\">必须指定\u003C\u002Fth>\n\u003Cth align=\"left\">默认值\u003C\u002Fth>\n\u003Cth align=\"left\">描述\u003C\u002Fth>\n\u003C\u002Ftr>\n\u003C\u002Fthead>\n\u003Ctbody>\n\u003Ctr>\n\u003Ctd align=\"left\">value\u003C\u002Ftd>\n\u003Ctd align=\"left\">String\u003C\u002Ftd>\n\u003Ctd align=\"left\">否\u003C\u002Ftd>\n\u003Ctd align=\"left\">""\u003C\u002Ftd>\n\u003Ctd align=\"left\">主键字段名\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">type\u003C\u002Ftd>\n\u003Ctd align=\"left\">Enum\u003C\u002Ftd>\n\u003Ctd align=\"left\">否\u003C\u002Ftd>\n\u003Ctd align=\"left\">IdType.NONE\u003C\u002Ftd>\n\u003Ctd align=\"left\">指定主键类型\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003C\u002Ftbody>\n\u003C\u002Ftable>\n\u003Ch3 id=\"toc-4\">IdType 主键类型\u003C\u002Fh3>\n\u003Ctable>\n\u003Cthead>\n\u003Ctr>\n\u003Cth align=\"left\">值\u003C\u002Fth>\n\u003Cth align=\"left\">描述\u003C\u002Fth>\n\u003C\u002Ftr>\n\u003C\u002Fthead>\n\u003Ctbody>\n\u003Ctr>\n\u003Ctd align=\"left\">AUTO\u003C\u002Ftd>\n\u003Ctd align=\"left\">数据库 ID 自增\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">NONE\u003C\u002Ftd>\n\u003Ctd align=\"left\">无状态，该类型为未设置主键类型（默认）\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">INPUT\u003C\u002Ftd>\n\u003Ctd align=\"left\">插入数据前，需自行设置主键的值\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">ASSIGN_ID\u003C\u002Ftd>\n\u003Ctd align=\"left\">分配 ID(主键类型为 Number(Long 和 Integer)或 String)(since 3.3.0),使用接口\u003Ccode>IdentifierGenerator\u003C\u002Fcode>的方法\u003Ccode>nextId\u003C\u002Fcode>(默认实现类为\u003Ccode>DefaultIdentifierGenerator\u003C\u002Fcode>雪花算法)\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">ASSIGN_UUID\u003C\u002Ftd>\n\u003Ctd align=\"left\">分配 UUID,主键类型为 String(since 3.3.0),使用接口\u003Ccode>IdentifierGenerator\u003C\u002Fcode>的方法\u003Ccode>nextUUID\u003C\u002Fcode> (默认 default 方法)\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">~~ID_WORKER~~\u003C\u002Ftd>\n\u003Ctd align=\"left\">分布式全局唯一 ID 长整型类型 (推荐使用 \u003Ccode>ASSIGN_ID\u003C\u002Fcode>)\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">~~UUID~~\u003C\u002Ftd>\n\u003Ctd align=\"left\">32 位 UUID 字符串 (推荐使用 \u003Ccode>ASSIGN_UUID\u003C\u002Fcode>)\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"left\">~~ID_WORKER_STR~~\u003C\u002Ftd>\n\u003Ctd align=\"left\">分布式全局唯一 ID 字符串类型 (推荐使用 \u003Ccode>ASSIGN_ID\u003C\u002Fcode>)\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003C\u002Ftbody>\n\u003C\u002Ftable>\n\u003Ch2 id=\"toc-5\">开始新增数据\u003C\u002Fh2>\n\u003Cp>测试表准备好后，我们准备开始演示新增数据。实际上，Mybatis Plus 对 Mapper 层和 Service 层都将常见的增删改查操作都封装好了，只需简单的继承，即可轻松搞定对数据的增删改查，本文重点讲解新增数据这块。\u003C\u002Fp>\n\u003Ch3 id=\"toc-6\">Mapper 层\u003C\u002Fh3>\n\u003Cp>定义一个 \u003Ccode>UserMapper\u003C\u002Fcode> , 让其继承 \u003Ccode>BaseMapper\u003C\u002Fcode> :\u003C\u002Fp>\n\u003Cdiv class=\"language-java\" data-ext=\"java\" data-code=\"public%20interface%20UserMapper%20extends%20BaseMapper%3CUser%3E%20%7B%0A%7D%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-java\">\u003Cspan class=\"token keyword\">public\u003C\u002Fspan> \u003Cspan class=\"token keyword\">interface\u003C\u002Fspan> \u003Cspan class=\"token class-name\">UserMapper\u003C\u002Fspan> \u003Cspan class=\"token keyword\">extends\u003C\u002Fspan> \u003Cspan class=\"token class-name\">BaseMapper\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token class-name\">User\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">{\u003C\u002Fspan>\n\u003Cspan class=\"token punctuation\">}\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>然后，注入 Mapper :\u003C\u002Fp>\n\u003Cdiv class=\"language-java\" data-ext=\"java\" data-code=\"%40Autowired%0Aprivate%20UserMapper%20userMapper%3B%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-java\">\u003Cspan class=\"token annotation punctuation\">@Autowired\u003C\u002Fspan>\n\u003Cspan class=\"token keyword\">private\u003C\u002Fspan> \u003Cspan class=\"token class-name\">UserMapper\u003C\u002Fspan> userMapper\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>\u003Ccode>BaseMapper\u003C\u002Fcode> 提供的新增方法仅一个 \u003Ccode>insert()\u003C\u002Fcode> 方法：\u003C\u002Fp>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167220330351372-ApDw.jpg\" loading=\"lazy\">\u003C\u002Fdiv>\n\u003C\u002Fp>\n\u003Cp>我们通过它测试一下添加数据，并获取主键 ID :\u003C\u002Fp>\n\u003Cdiv class=\"language-dockerfile\" data-ext=\"dockerfile\" data-code=\"User%20user%20%3D%20new%20User()%3B%0Auser.setName(%22%E5%BC%A0%E4%B8%89%22)%3B%0Auser.setAge(30)%3B%0Auser.setGender(1)%3B%0A%0AuserMapper.insert(user)%3B%0A%0A%2F%2F%20%E8%8E%B7%E5%8F%96%E6%8F%92%E5%85%A5%E6%95%B0%E6%8D%AE%E7%9A%84%E4%B8%BB%E9%94%AE%20ID%0ALong%20id%20%3D%20user.getId()%3B%0A%0ASystem.out.println(%22id%3A%22%20%2B%20id)%3B%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-dockerfile\">\u003Cspan class=\"token instruction\">\u003Cspan class=\"token keyword\">User\u003C\u002Fspan> user = new User();\u003C\u002Fspan>\nuser.setName(\"张三\");\nuser.setAge(30);\nuser.setGender(1);\n\nuserMapper.insert(user);\n\n\u002F\u002F 获取插入数据的主键 ID\nLong id = user.getId();\n\nSystem.out.println(\"id:\" + id);\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>怎么样，是不是非常简单呢！\u003C\u002Fp>\n\u003Ch3 id=\"toc-7\">Service 层\u003C\u002Fh3>\n\u003Cp>Mybatis Plus 同样也封装了通用的 Service 层 CRUD 操作，并且提供了更丰富的方法。接下来，我们上手看 Service 层的代码结构，如下图：\u003C\u002Fp>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167204808139593-dWMf.jpg\" loading=\"lazy\" title=\"定义 Service 层\" alt=\"定义 Service 层\">\u003C\u002Fdiv>\u003Cspan class=\"image-caption\">定义 Service 层\u003C\u002Fspan>\n\u003C\u002Fp>\n\u003Cp>先定义 \u003Ccode>UserService\u003C\u002Fcode> 接口 ，让其继承自 \u003Ccode>IService\u003C\u002Fcode>:\u003C\u002Fp>\n\u003Cdiv class=\"language-java\" data-ext=\"java\" data-code=\"public%20interface%20UserService%20extends%20IService%3CUser%3E%20%7B%0A%7D%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-java\">\u003Cspan class=\"token keyword\">public\u003C\u002Fspan> \u003Cspan class=\"token keyword\">interface\u003C\u002Fspan> \u003Cspan class=\"token class-name\">UserService\u003C\u002Fspan> \u003Cspan class=\"token keyword\">extends\u003C\u002Fspan> \u003Cspan class=\"token class-name\">IService\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token class-name\">User\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">{\u003C\u002Fspan>\n\u003Cspan class=\"token punctuation\">}\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>再定义实现类 \u003Ccode>UserServiceImpl\u003C\u002Fcode>，让其继承自 \u003Ccode>ServiceImpl\u003C\u002Fcode>, 同时实现 \u003Ccode>UserService\u003C\u002Fcode> 接口，这样就可以让 \u003Ccode>UserService\u003C\u002Fcode> 拥有了基础通用的 CRUD 功能，当然，实际开发中，业务会更加复杂，就需要向 \u003Ccode>IService\u003C\u002Fcode> 接口自定义方法并实现:\u003C\u002Fp>\n\u003Cdiv class=\"language-java\" data-ext=\"java\" data-code=\"%40Service%0Apublic%20class%20UserServiceImpl%20extends%20ServiceImpl%3CUserMapper%2C%20User%3E%20implements%20UserService%20%7B%0A%7D%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-java\">\u003Cspan class=\"token annotation punctuation\">@Service\u003C\u002Fspan>\n\u003Cspan class=\"token keyword\">public\u003C\u002Fspan> \u003Cspan class=\"token keyword\">class\u003C\u002Fspan> \u003Cspan class=\"token class-name\">UserServiceImpl\u003C\u002Fspan> \u003Cspan class=\"token keyword\">extends\u003C\u002Fspan> \u003Cspan class=\"token class-name\">ServiceImpl\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token class-name\">UserMapper\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token class-name\">User\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> \u003Cspan class=\"token keyword\">implements\u003C\u002Fspan> \u003Cspan class=\"token class-name\">UserService\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">{\u003C\u002Fspan>\n\u003Cspan class=\"token punctuation\">}\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>注入 \u003Ccode>UserService\u003C\u002Fcode> :\u003C\u002Fp>\n\u003Cdiv class=\"language-java\" data-ext=\"java\" data-code=\"%40Autowired%0Aprivate%20UserService%20userService%3B%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-java\">\u003Cspan class=\"token annotation punctuation\">@Autowired\u003C\u002Fspan>\n\u003Cspan class=\"token keyword\">private\u003C\u002Fspan> \u003Cspan class=\"token class-name\">UserService\u003C\u002Fspan> userService\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>与 Mapper 层不同的是，Service 层的新增方法均以 \u003Ccode>save\u003C\u002Fcode> 开头，并且功能更丰富，来看看都提供了哪些方法：\u003C\u002Fp>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167204984846713-tDOT.jpg\" loading=\"lazy\" title=\"新增数据共有 6 个方法\" alt=\"新增数据共有 6 个方法\">\u003C\u002Fdiv>\u003Cspan class=\"image-caption\">新增数据共有 6 个方法\u003C\u002Fspan>\n\u003C\u002Fp>\n\u003Cp>简单解释下每个方法的作用，以作了解：\u003C\u002Fp>\n\u003Cdiv class=\"language-java\" data-ext=\"java\" data-code=\"%2F%2F%20%E6%96%B0%E5%A2%9E%E6%95%B0%E6%8D%AE%0Asava(T)%20%3A%20boolean%0A%2F%2F%20%E4%BC%AA%E6%89%B9%E9%87%8F%E6%8F%92%E5%85%A5%EF%BC%8C%E5%AE%9E%E9%99%85%E4%B8%8A%E6%98%AF%E9%80%9A%E8%BF%87%20for%20%E5%BE%AA%E7%8E%AF%E4%B8%80%E6%9D%A1%E4%B8%80%E6%9D%A1%E7%9A%84%E6%8F%92%E5%85%A5%0AsavaBatch(Collection%3CT%3E)%20%3A%20boolean%0A%2F%2F%20%E4%BC%AA%E6%89%B9%E9%87%8F%E6%8F%92%E5%85%A5%EF%BC%8Cint%20%E8%A1%A8%E7%A4%BA%E6%89%B9%E9%87%8F%E6%8F%90%E4%BA%A4%E6%95%B0%EF%BC%8C%E9%BB%98%E8%AE%A4%E4%B8%BA%201000%0AsavaBatch(Collection%3CT%3E%2C%20int)%20%3A%20boolean%0A%2F%2F%20%E6%96%B0%E5%A2%9E%E6%88%96%E6%9B%B4%E6%96%B0(%E5%8D%95%E6%9D%A1%E6%95%B0%E6%8D%AE)%0AsaveOrUpdate(T)%20%3A%20boolean%0A%2F%2F%20%E6%89%B9%E9%87%8F%E6%96%B0%E5%A2%9E%E6%88%96%E6%9B%B4%E6%96%B0%0AsaveOrUpdateBatch(Collection%3CT%3E)%20%3A%20boolean%0A%2F%2F%20%E6%89%B9%E9%87%8F%E6%96%B0%E5%A2%9E%E6%88%96%E6%9B%B4%E6%96%B0(%E5%8F%AF%E6%8C%87%E5%AE%9A%E6%89%B9%E9%87%8F%E6%8F%90%E4%BA%A4%E6%95%B0)%0AsaveOrUpdateBatch(Collection%3CT%3E%2C%20int)%20%3A%20boolean%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-java\">\u003Cspan class=\"token comment\">\u002F\u002F 新增数据\u003C\u002Fspan>\n\u003Cspan class=\"token function\">sava\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token class-name\">T\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token operator\">:\u003C\u002Fspan> \u003Cspan class=\"token keyword\">boolean\u003C\u002Fspan>\n\u003Cspan class=\"token comment\">\u002F\u002F 伪批量插入，实际上是通过 for 循环一条一条的插入\u003C\u002Fspan>\n\u003Cspan class=\"token function\">savaBatch\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token class-name\">Collection\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token class-name\">T\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token operator\">:\u003C\u002Fspan> \u003Cspan class=\"token keyword\">boolean\u003C\u002Fspan>\n\u003Cspan class=\"token comment\">\u002F\u002F 伪批量插入，int 表示批量提交数，默认为 1000\u003C\u002Fspan>\n\u003Cspan class=\"token function\">savaBatch\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token class-name\">Collection\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token class-name\">T\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token keyword\">int\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token operator\">:\u003C\u002Fspan> \u003Cspan class=\"token keyword\">boolean\u003C\u002Fspan>\n\u003Cspan class=\"token comment\">\u002F\u002F 新增或更新(单条数据)\u003C\u002Fspan>\n\u003Cspan class=\"token function\">saveOrUpdate\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token class-name\">T\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token operator\">:\u003C\u002Fspan> \u003Cspan class=\"token keyword\">boolean\u003C\u002Fspan>\n\u003Cspan class=\"token comment\">\u002F\u002F 批量新增或更新\u003C\u002Fspan>\n\u003Cspan class=\"token function\">saveOrUpdateBatch\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token class-name\">Collection\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token class-name\">T\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token operator\">:\u003C\u002Fspan> \u003Cspan class=\"token keyword\">boolean\u003C\u002Fspan>\n\u003Cspan class=\"token comment\">\u002F\u002F 批量新增或更新(可指定批量提交数)\u003C\u002Fspan>\n\u003Cspan class=\"token function\">saveOrUpdateBatch\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token class-name\">Collection\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token class-name\">T\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token keyword\">int\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token operator\">:\u003C\u002Fspan> \u003Cspan class=\"token keyword\">boolean\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>大致看完后，上手测试一下。\u003C\u002Fp>\n\u003Ch4 id=\"toc-8\">sava(T)\u003C\u002Fh4>\n\u003Cp>\u003Cstrong>简单的新增数据\u003C\u002Fstrong>，示例代码如下：\u003C\u002Fp>\n\u003Cdiv class=\"language-sql\" data-ext=\"sql\" data-code=\"%2F%2F%20%E6%96%B0%E5%A2%9E%E6%95%B0%E6%8D%AE%0A%2F%2F%20%E5%AE%9E%E9%99%85%E6%89%A7%E8%A1%8C%20SQL%20%3A%20INSERT%20INTO%20user%20(%20name%2C%20age%2C%20gender%20)%20VALUES%20(%20'%E5%BC%A0%E4%B8%89%20111'%2C%2030%2C%201%20)%0AUser%20user%20%3D%20new%20User()%3B%0Auser.setName(%22%E5%BC%A0%E4%B8%89%20111%22)%3B%0Auser.setAge(30)%3B%0Auser.setGender(1)%3B%0A%0Aboolean%20isSuccess%20%3D%20userService.save(user)%3B%0A%0A%2F%2F%20%E8%BF%94%E5%9B%9E%E4%B8%BB%E9%94%AEID%0ALong%20id%20%3D%20user.getId()%3B%0ASystem.out.println(%22isSuccess%3A%22%20%2B%20isSuccess)%3B%0ASystem.out.println(%22%E4%B8%BB%E9%94%AE%20ID%3A%20%22%20%2B%20id)%3B%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-sql\">\u003Cspan class=\"token comment\">\u002F\u002F 新增数据\u003C\u002Fspan>\n\u003Cspan class=\"token comment\">\u002F\u002F 实际执行 SQL : INSERT INTO user ( name, age, gender ) VALUES ( '张三111', 30, 1 )\u003C\u002Fspan>\n\u003Cspan class=\"token keyword\">User\u003C\u002Fspan> \u003Cspan class=\"token keyword\">user\u003C\u002Fspan> \u003Cspan class=\"token operator\">=\u003C\u002Fspan> new \u003Cspan class=\"token keyword\">User\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token keyword\">user\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>setName\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token string\">\"张三111\"\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token keyword\">user\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>setAge\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token number\">30\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token keyword\">user\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>setGender\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token number\">1\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\n\u003Cspan class=\"token keyword\">boolean\u003C\u002Fspan> isSuccess \u003Cspan class=\"token operator\">=\u003C\u002Fspan> userService\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token keyword\">save\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token keyword\">user\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\n\u003Cspan class=\"token comment\">\u002F\u002F 返回主键ID\u003C\u002Fspan>\nLong id \u003Cspan class=\"token operator\">=\u003C\u002Fspan> \u003Cspan class=\"token keyword\">user\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>getId\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\nSystem\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token keyword\">out\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>println\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token string\">\"isSuccess:\"\u003C\u002Fspan> \u003Cspan class=\"token operator\">+\u003C\u002Fspan> isSuccess\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\nSystem\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token keyword\">out\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>println\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token string\">\"主键 ID: \"\u003C\u002Fspan> \u003Cspan class=\"token operator\">+\u003C\u002Fspan> id\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Ch4 id=\"toc-9\">savaBatch(Collection\u003CT>)\u003C\u002Fh4>\n\u003Cp>\u003Cstrong>伪批量插入\u003C\u002Fstrong>，注意，命名虽然包含了批量的意思，但这不是真的批量插入，不信的话，我们来实际测试一下：\u003C\u002Fp>\n\u003Cdiv class=\"language-dockerfile\" data-ext=\"dockerfile\" data-code=\"%2F%2F%20%E6%89%B9%E9%87%8F%E6%8F%92%E5%85%A5%0AList%3CUser%3E%20users%20%3D%20new%20ArrayList%3C%3E()%3B%0Afor%20(int%20i%20%3D%200%3B%20i%20%3C%205%3B%20i%2B%2B)%20%7B%0A%20%20%20%20User%20user%20%3D%20new%20User()%3B%0A%20%20%20%20user.setName(%22%E5%BC%A0%E4%B8%89%22%20%2B%20i)%3B%0A%20%20%20%20user.setAge(i)%3B%0A%20%20%20%20user.setGender(1)%3B%0A%20%20%20%20users.add(user)%3B%0A%7D%0Aboolean%20isSuccess%20%3D%20userService.saveBatch(users)%3B%0ASystem.out.println(%22isSuccess%3A%22%20%2B%20isSuccess)%3B%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-dockerfile\">\u002F\u002F 批量插入\nList<User> users = new ArrayList<>();\nfor (int i = 0; i < 5; i++) {\n    \u003Cspan class=\"token instruction\">\u003Cspan class=\"token keyword\">User\u003C\u002Fspan> user = new User();\u003C\u002Fspan>\n    user.setName(\"张三\" + i);\n    user.setAge(i);\n    user.setGender(1);\n    users.add(user);\n}\nboolean isSuccess = userService.saveBatch(users);\nSystem.out.println(\"isSuccess:\" + isSuccess);\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>执行代码，实际执行的 SQL 如下：\u003C\u002Fp>\n\u003Cblockquote>\n\u003Cp>TIP : 如何打印实际执行的 SQL, 可参考之前小节的 《Mybatis Plus 打印 SQL 语句（包含执行耗时）》\u003Cspan>\u003Csvg xmlns=\"http:\u002F\u002Fwww.w3.org\u002F2000\u002Fsvg\" style=\"color: #aaa; margin-left: 3px;\" aria-hidden=\"true\" focusable=\"false\" x=\"0px\" y=\"0px\" viewBox=\"0 0 100 100\" width=\"15\" height=\"15\" class=\"icon outbound\">\u003Cpath fill=\"currentColor\" d=\"M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z\">\u003C\u002Fpath> \u003Cpolygon fill=\"currentColor\" points=\"45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9\">\u003C\u002Fpolygon>\u003C\u002Fsvg> \u003Cspan class=\"sr-only\">\u003C\u002Fspan>\u003C\u002Fspan>。\u003C\u002Fp>\n\u003C\u002Fblockquote>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167211863047181-DEdJ.jpg\" loading=\"lazy\" title=\"批量插入输入 SQL 打印\" alt=\"批量插入输入 SQL 打印\">\u003C\u002Fdiv>\u003Cspan class=\"image-caption\">批量插入输入 SQL 打印\u003C\u002Fspan>\n\u003C\u002Fp>\n\u003Cp>可以看到，并不是 \u003Ccode>insert into user (xxx) values (xxx),(xxx),(xxx)\u003C\u002Fcode> 这种批量形式，还是一条一条插入的。\u003C\u002Fp>\n\u003Ch5 id=\"toc-10\">批量新增源码分析\u003C\u002Fh5>\n\u003Cp>我们来看下源码, 内部的\u003Ccode>saveBatch()\u003C\u002Fcode> 方法默认的批量提交阀值参数，数值为 1000， 即达到 1000 条批量提交一次，继续点进去看：：\u003C\u002Fp>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167212963055320-ODNh.jpg\" loading=\"lazy\">\u003C\u002Fdiv>\n\u003C\u002Fp>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167211902799533.jpg\" loading=\"lazy\" title=\"源码分析\" alt=\"源码分析\">\u003C\u002Fdiv>\u003Cspan class=\"image-caption\">源码分析\u003C\u002Fspan>\n\u003C\u002Fp>\n\u003Cdiv class=\"language-java\" data-ext=\"java\" data-code=\"public%20boolean%20saveBatch(Collection%3CT%3E%20entityList%2C%20int%20batchSize)%20%7B%0A%20%20%20%20%20%20%20%20%2F%2F%20%E8%8E%B7%E5%8F%96%E9%A2%84%E7%BC%96%E8%AF%91%E7%9A%84%E6%8F%92%E5%85%A5%20SQL%0A%20%20%20%20%20%20%20%20String%20sqlStatement%20%3D%20this.getSqlStatement(SqlMethod.INSERT_ONE)%3B%0A%20%20%20%20%20%20%20%20%2F%2F%20for%20%E5%BE%AA%E7%8E%AF%E6%89%A7%E8%A1%8C%20insert%0A%20%20%20%20%20%20%20%20return%20this.executeBatch(entityList%2C%20batchSize%2C%20(sqlSession%2C%20entity)%20-%3E%20%7B%0A%20%20%20%20%20%20%20%20%20%20%20%20sqlSession.insert(sqlStatement%2C%20entity)%3B%0A%20%20%20%20%20%20%20%20%7D)%3B%0A%20%20%20%20%7D%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-java\">\u003Cspan class=\"token keyword\">public\u003C\u002Fspan> \u003Cspan class=\"token keyword\">boolean\u003C\u002Fspan> \u003Cspan class=\"token function\">saveBatch\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token class-name\">Collection\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token class-name\">T\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> entityList\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token keyword\">int\u003C\u002Fspan> batchSize\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">{\u003C\u002Fspan>\n        \u003Cspan class=\"token comment\">\u002F\u002F 获取预编译的插入 SQL\u003C\u002Fspan>\n        \u003Cspan class=\"token class-name\">String\u003C\u002Fspan> sqlStatement \u003Cspan class=\"token operator\">=\u003C\u002Fspan> \u003Cspan class=\"token keyword\">this\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">getSqlStatement\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token class-name\">SqlMethod\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token constant\">INSERT_ONE\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n        \u003Cspan class=\"token comment\">\u002F\u002F for 循环执行 insert\u003C\u002Fspan>\n        \u003Cspan class=\"token keyword\">return\u003C\u002Fspan> \u003Cspan class=\"token keyword\">this\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">executeBatch\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>entityList\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> batchSize\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>sqlSession\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> entity\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token operator\">->\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">{\u003C\u002Fspan>\n            sqlSession\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">insert\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>sqlStatement\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> entity\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n        \u003Cspan class=\"token punctuation\">}\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n    \u003Cspan class=\"token punctuation\">}\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>再看下 \u003Ccode>SqlMethod.INSERT_ONE\u003C\u002Fcode> 这个枚举，描述信息为\u003Cem>插入一条数据\u003C\u002Fem>：\u003C\u002Fp>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167213598609592-GcND.jpg\" loading=\"lazy\">\u003C\u002Fdiv>\n\u003C\u002Fp>\n\u003Cp>继续往 \u003Ccode>executeBatch()\u003C\u002Fcode> 方法里看，瞅瞅它这个批量到底是怎么处理的，具体每行代码的意思，都加了注释：\u003C\u002Fp>\n\u003Cdiv class=\"language-java\" data-ext=\"java\" data-code=\"%20%20%20%20public%20static%20%3CE%3E%20boolean%20executeBatch(Class%3C%3F%3E%20entityClass%2C%20Log%20log%2C%20Collection%3CE%3E%20list%2C%20int%20batchSize%2C%20BiConsumer%3CSqlSession%2C%20E%3E%20consumer)%20%7B%0A%20%20%20%20%09%2F%2F%20%E6%96%AD%E8%A8%80%E9%9C%80%E8%A6%81%E6%89%B9%E5%A4%84%E7%90%86%E6%95%B0%E6%8D%AE%E9%9B%86%E5%A4%A7%E5%B0%8F%E4%B8%8D%E7%AD%89%E4%BA%8E1%0A%20%20%20%20%20%20%20%20Assert.isFalse(batchSize%20%3C%201%2C%20%22batchSize%20must%20not%20be%20less%20than%20one%22%2C%20new%20Object%5B0%5D)%3B%0A%20%20%20%20%20%20%20%20%2F%2F%20%E5%88%A4%E7%A9%BA%E6%95%B0%E6%8D%AE%E9%9B%86%EF%BC%8C%E8%8B%A5%E4%B8%8D%E4%B8%BA%E7%A9%BA%EF%BC%8C%E5%88%99%E5%BC%80%E5%A7%8B%E6%89%A7%E8%A1%8C%E6%89%B9%E9%87%8F%E5%A4%84%E7%90%86%0A%20%20%20%20%20%20%20%20return%20!CollectionUtils.isEmpty(list)%20%26%26%20executeBatch(entityClass%2C%20log%2C%20(sqlSession)%20-%3E%20%7B%0A%20%20%20%20%20%20%20%20%09%0A%20%20%20%20%20%20%20%20%20%20%20%20int%20size%20%3D%20list.size()%3B%0A%20%20%20%20%20%20%20%20%20%20%20%20%2F%2F%20%E5%B0%86%E6%89%B9%E5%A4%84%E7%90%86%E5%A4%A7%E5%B0%8F%E4%B8%8E%E4%BC%A0%E5%85%A5%E7%9A%84%E6%93%8D%E4%BD%9C%E9%9B%86%E5%90%88%E5%A4%A7%E5%B0%8F%E8%BF%9B%E8%A1%8C%E6%AF%94%E8%BE%83%EF%BC%8C%E5%8F%96%E6%9C%80%E5%B0%8F%E7%9A%84%E9%82%A3%E4%B8%AA%0A%20%20%20%20%20%20%20%20%20%20%20%20int%20idxLimit%20%3D%20Math.min(batchSize%2C%20size)%3B%0A%20%20%20%20%20%20%20%20%20%20%20%20int%20i%20%3D%201%3B%0A%20%20%20%20%20%20%20%20%20%20%20%20%2F%2F%20%E8%BF%AD%E4%BB%A3%E5%99%A8%E5%BE%AA%E7%8E%AF%0A%20%20%20%20%20%20%20%20%20%20%20%20for(Iterator%20var7%20%3D%20list.iterator()%3B%20var7.hasNext()%3B%20%2B%2Bi)%20%7B%0A%20%20%20%20%20%20%20%20%20%20%20%20%09%2F%2F%20%E8%8E%B7%E5%8F%96%E5%BD%93%E5%89%8D%E9%9C%80%E8%A6%81%E6%89%A7%E8%A1%8C%E7%9A%84%E6%95%B0%E6%8D%AE%E5%BA%93%E6%93%8D%E4%BD%9C%0A%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20E%20element%20%3D%20var7.next()%3B%0A%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%2F%2F%20%E5%9B%9E%E8%B0%83%20sqlSession.insert()%20%E6%96%B9%E6%B3%95%0A%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20consumer.accept(sqlSession%2C%20element)%3B%0A%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%2F%2F%20%E5%88%A4%E6%96%AD%E6%98%AF%E5%90%A6%E8%BE%BE%E5%88%B0%E9%9C%80%E8%A6%81%E6%89%B9%E5%A4%84%E7%90%86%E7%9A%84%E9%98%80%E5%80%BC%0A%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20if%20(i%20%3D%3D%20idxLimit)%20%7B%0A%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%09%2F%2F%20%E5%BC%80%E5%A7%8B%E6%89%B9%E5%A4%84%E7%90%86%EF%BC%8C%E6%AD%A4%E6%96%B9%E6%B3%95%E6%89%A7%E8%A1%8C%E5%B9%B6%E6%B8%85%E9%99%A4%E7%BC%93%E5%AD%98%E5%9C%A8%20JDBC%20%E9%A9%B1%E5%8A%A8%E7%B1%BB%E4%B8%AD%E7%9A%84%E6%89%A7%E8%A1%8C%E8%AF%AD%E5%8F%A5%0A%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20sqlSession.flushStatements()%3B%0A%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20idxLimit%20%3D%20Math.min(idxLimit%20%2B%20batchSize%2C%20size)%3B%0A%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%7D%0A%20%20%20%20%20%20%20%20%20%20%20%20%7D%0A%20%20%20%20%20%20%20%20%7D)%3B%0A%20%20%20%20%7D%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-java\">    \u003Cspan class=\"token keyword\">public\u003C\u002Fspan> \u003Cspan class=\"token keyword\">static\u003C\u002Fspan> \u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token class-name\">E\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> \u003Cspan class=\"token keyword\">boolean\u003C\u002Fspan> \u003Cspan class=\"token function\">executeBatch\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token class-name\">Class\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token operator\">?\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> entityClass\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token class-name\">Log\u003C\u002Fspan> log\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token class-name\">Collection\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token class-name\">E\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> list\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token keyword\">int\u003C\u002Fspan> batchSize\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token class-name\">BiConsumer\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token class-name\">SqlSession\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token class-name\">E\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> consumer\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">{\u003C\u002Fspan>\n    \t\u003Cspan class=\"token comment\">\u002F\u002F 断言需要批处理数据集大小不等于1\u003C\u002Fspan>\n        \u003Cspan class=\"token class-name\">Assert\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">isFalse\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>batchSize \u003Cspan class=\"token operator\"><\u003C\u002Fspan> \u003Cspan class=\"token number\">1\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token string\">\"batchSize must not be less than one\"\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token keyword\">new\u003C\u002Fspan> \u003Cspan class=\"token class-name\">Object\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">[\u003C\u002Fspan>\u003Cspan class=\"token number\">0\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">]\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n        \u003Cspan class=\"token comment\">\u002F\u002F 判空数据集，若不为空，则开始执行批量处理\u003C\u002Fspan>\n        \u003Cspan class=\"token keyword\">return\u003C\u002Fspan> \u003Cspan class=\"token operator\">!\u003C\u002Fspan>\u003Cspan class=\"token class-name\">CollectionUtils\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">isEmpty\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>list\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token operator\">&&\u003C\u002Fspan> \u003Cspan class=\"token function\">executeBatch\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>entityClass\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> log\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>sqlSession\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token operator\">->\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">{\u003C\u002Fspan>\n        \t\n            \u003Cspan class=\"token keyword\">int\u003C\u002Fspan> size \u003Cspan class=\"token operator\">=\u003C\u002Fspan> list\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">size\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n            \u003Cspan class=\"token comment\">\u002F\u002F 将批处理大小与传入的操作集合大小进行比较，取最小的那个\u003C\u002Fspan>\n            \u003Cspan class=\"token keyword\">int\u003C\u002Fspan> idxLimit \u003Cspan class=\"token operator\">=\u003C\u002Fspan> \u003Cspan class=\"token class-name\">Math\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">min\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>batchSize\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> size\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n            \u003Cspan class=\"token keyword\">int\u003C\u002Fspan> i \u003Cspan class=\"token operator\">=\u003C\u002Fspan> \u003Cspan class=\"token number\">1\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n            \u003Cspan class=\"token comment\">\u002F\u002F 迭代器循环\u003C\u002Fspan>\n            \u003Cspan class=\"token keyword\">for\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token class-name\">Iterator\u003C\u002Fspan> var7 \u003Cspan class=\"token operator\">=\u003C\u002Fspan> list\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">iterator\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan> var7\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">hasNext\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan> \u003Cspan class=\"token operator\">++\u003C\u002Fspan>i\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">{\u003C\u002Fspan>\n            \t\u003Cspan class=\"token comment\">\u002F\u002F 获取当前需要执行的数据库操作\u003C\u002Fspan>\n                \u003Cspan class=\"token class-name\">E\u003C\u002Fspan> element \u003Cspan class=\"token operator\">=\u003C\u002Fspan> var7\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">next\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n                \u003Cspan class=\"token comment\">\u002F\u002F 回调 sqlSession.insert() 方法\u003C\u002Fspan>\n                consumer\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">accept\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>sqlSession\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> element\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n                \u003Cspan class=\"token comment\">\u002F\u002F 判断是否达到需要批处理的阀值\u003C\u002Fspan>\n                \u003Cspan class=\"token keyword\">if\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>i \u003Cspan class=\"token operator\">==\u003C\u002Fspan> idxLimit\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">{\u003C\u002Fspan>\n                \t\u003Cspan class=\"token comment\">\u002F\u002F 开始批处理，此方法执行并清除缓存在 JDBC 驱动类中的执行语句\u003C\u002Fspan>\n                    sqlSession\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">flushStatements\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n                    idxLimit \u003Cspan class=\"token operator\">=\u003C\u002Fspan> \u003Cspan class=\"token class-name\">Math\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">min\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>idxLimit \u003Cspan class=\"token operator\">+\u003C\u002Fspan> batchSize\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> size\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n                \u003Cspan class=\"token punctuation\">}\u003C\u002Fspan>\n            \u003Cspan class=\"token punctuation\">}\u003C\u002Fspan>\n        \u003Cspan class=\"token punctuation\">}\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n    \u003Cspan class=\"token punctuation\">}\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>看完就明白了，相比较自己手动 \u003Ccode>for\u003C\u002Fcode> 循环执行插入，Mybatis Plus 这个伪批量插入性能会更好些，内部会将每次的插入语句缓存起来，等到达到 1000 条的时候，才会统一推给数据库，虽然最终在数据库那边还是一条一条的执行 INSERT，但还是在和数据库交互的 IO 上做了优化。\u003C\u002Fp>\n\u003Ch4 id=\"toc-11\">savaBatch(Collection\u003CT>, int)\u003C\u002Fh4>\n\u003Cp>多了个 \u003Ccode>batchSize\u003C\u002Fcode> 参数，可以手动指定批处理的大小，即多少 SQL 操作执行一次，默认为 1000。\u003C\u002Fp>\n\u003Ch4 id=\"toc-12\">saveOrUpdate(T)\u003C\u002Fh4>\n\u003Cp>\u003Cstrong>保存或者更新\u003C\u002Fstrong>。即当你需要执行的数据，数据库中不存在时，就执行插入操作：\u003C\u002Fp>\n\u003Cdiv class=\"language-sql\" data-ext=\"sql\" data-code=\"%2F%2F%20%E5%AE%9E%E9%99%85%E6%89%A7%E8%A1%8C%20SQL%20%3A%20INSERT%20INTO%20user%20(%20name%2C%20age%2C%20gender%20)%20VALUES%20(%20'%E5%B0%8F%E5%BC%A0%E4%B8%89'%2C%2060%2C%201%20)%0AUser%20user%20%3D%20new%20User()%3B%0Auser.setName(%22%E5%B0%8F%E5%BC%A0%E4%B8%89%22)%3B%0Auser.setAge(60)%3B%0Auser.setGender(1)%3B%0AuserService.saveOrUpdate(user)%3B%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-sql\">\u003Cspan class=\"token comment\">\u002F\u002F 实际执行 SQL : INSERT INTO user ( name, age, gender ) VALUES ( '张小三', 60, 1 )\u003C\u002Fspan>\n\u003Cspan class=\"token keyword\">User\u003C\u002Fspan> \u003Cspan class=\"token keyword\">user\u003C\u002Fspan> \u003Cspan class=\"token operator\">=\u003C\u002Fspan> new \u003Cspan class=\"token keyword\">User\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token keyword\">user\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>setName\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token string\">\"张小三\"\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token keyword\">user\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>setAge\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token number\">60\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token keyword\">user\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>setGender\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token number\">1\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\nuserService\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>saveOrUpdate\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token keyword\">user\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>当你需要执行的数据，数据库中已存在时，就执行更新操作。框架是如何判断该记录是否存在呢？ 如设置了主键 ID，因为主键 ID 必须是唯一的，Mybatis Plus 会先执行查询操作，判断数据是否存在，存在即执行更新，否则，执行插入操作：\u003C\u002Fp>\n\u003Cdiv class=\"language-dockerfile\" data-ext=\"dockerfile\" data-code=\"User%20user%20%3D%20new%20User()%3B%0A%2F%2F%20%E8%AE%BE%E7%BD%AE%E4%BA%86%E4%B8%BB%E9%94%AE%E5%AD%97%E6%AE%B5%0Auser.setId(21L)%3B%0Auser.setName(%22%E5%B0%8F%E5%BC%A0%E4%B8%89%22)%3B%0Auser.setAge(60)%3B%0Auser.setGender(1)%3B%0AuserService.saveOrUpdate(user)%3B%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-dockerfile\">\u003Cspan class=\"token instruction\">\u003Cspan class=\"token keyword\">User\u003C\u002Fspan> user = new User();\u003C\u002Fspan>\n\u002F\u002F 设置了主键字段\nuser.setId(21L);\nuser.setName(\"张小三\");\nuser.setAge(60);\nuser.setGender(1);\nuserService.saveOrUpdate(user);\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>具体执行 SQL 如下：\u003C\u002Fp>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167212563888187-JSqc.jpg\" loading=\"lazy\">\u003C\u002Fdiv>\n\u003C\u002Fp>\n\u003Ch4 id=\"toc-13\">saveOrUpdateBatch(Collection\u003CT>)\u003C\u002Fh4>\n\u003Cp>批量保存或者更新，示例代码如下：\u003C\u002Fp>\n\u003Cdiv class=\"language-dockerfile\" data-ext=\"dockerfile\" data-code=\"List%3CUser%3E%20users%20%3D%20new%20ArrayList%3C%3E()%3B%0Afor%20(int%20i%20%3D%200%3B%20i%20%3C%205%3B%20i%2B%2B)%20%7B%0A%20%20%20%20User%20user%20%3D%20new%20User()%3B%0A%20%20%20%20user.setId(Long.valueOf(i))%3B%0A%20%20%20%20user.setName(%22%E5%BC%A0%E4%B8%89%22%20%2B%20i)%3B%0A%20%20%20%20user.setAge(i%2B1)%3B%0A%20%20%20%20user.setGender(1)%3B%0A%20%20%20%20users.add(user)%3B%0A%7D%0AuserService.saveOrUpdateBatch(users)%3B%0A\">\n        \u003Cbutton class=\"vp-copy-code-button\" data-copy data-copied=\"已复制\" aria-label=\"复制代码\">\u003C\u002Fbutton>\n        \u003Cpre>\u003Ccode class=\"language-dockerfile\">List<User> users = new ArrayList<>();\nfor (int i = 0; i < 5; i++) {\n    \u003Cspan class=\"token instruction\">\u003Cspan class=\"token keyword\">User\u003C\u002Fspan> user = new User();\u003C\u002Fspan>\n    user.setId(Long.valueOf(i));\n    user.setName(\"张三\" + i);\n    user.setAge(i+1);\n    user.setGender(1);\n    users.add(user);\n}\nuserService.saveOrUpdateBatch(users);\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Ch4 id=\"toc-14\">saveOrUpdateBatch(Collection\u003CT>, int)\u003C\u002Fh4>\n\u003Cp>批量保存或者更新（可手动指定批量大小），示例代码如下：\u003C\u002Fp>"]