[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"site-config":3,"primary-menu":6,"cat-mybatis-plus":85,"catposts-mybatis-plus":97,"post-detail-post-mybatisplus-page-query-cf6b396c":484},{"config":4,"socialLinks":5},null,[],{"metadata":7,"spec":10,"menuItems":20},{"name":8,"creationTimestamp":9},"primary","2026-09-12T06:13:55.024154Z",{"displayName":11,"menuItems":12},"主菜单",[13,14,15,16,17,18,19],"88c3f10b-321c-4092-86a8-70db00251b74","menu-item-izrtmxer","c4c814d1-0c2c-456b-8c96-4864965fee94","menu-item-column","menu-item-tools","menu-item-zsxq","menu-item-ocrxlczu",[21,30,40,49,58,67,76],{"displayName":22,"metadata":23,"spec":25,"status":28,"children":29},"首页",{"name":13,"creationTimestamp":24},"2026-09-12T06:13:54.422830Z",{"displayName":22,"href":26,"priority":27,"menuName":8},"\u002F",0,{"displayName":22,"href":26},[],{"displayName":31,"metadata":32,"spec":34,"status":38,"children":39},"Java面试八股",{"name":14,"creationTimestamp":33},"2026-09-13T09:42:02.854891Z",{"displayName":31,"href":35,"target":36,"priority":37,"menuName":8},"\u002Fjava-interview","_self",1,{"displayName":31,"href":35},[],{"displayName":41,"metadata":42,"spec":44,"status":47,"children":48},"文章",{"name":15,"creationTimestamp":43},"2026-09-12T06:13:54.457307Z",{"displayName":41,"href":45,"priority":46,"menuName":8},"\u002Farchives",2,{"displayName":41,"href":45},[],{"displayName":50,"metadata":51,"spec":53,"status":56,"children":57},"项目实战",{"name":16,"creationTimestamp":52},"2026-09-14T00:35:08.138170Z",{"displayName":50,"href":54,"target":36,"priority":55,"menuName":8},"\u002Fcolumn",3,{"displayName":50,"href":54},[],{"displayName":59,"metadata":60,"spec":62,"status":65,"children":66},"在线工具",{"name":17,"creationTimestamp":61},"2026-09-14T00:35:08.171474Z",{"displayName":59,"href":63,"target":36,"priority":64,"menuName":8},"\u002Ftools",4,{"displayName":59,"href":63},[],{"displayName":68,"metadata":69,"spec":71,"status":74,"children":75},"知识星球",{"name":18,"creationTimestamp":70},"2026-09-14T00:35:08.199145Z",{"displayName":68,"href":72,"target":36,"priority":73,"menuName":8},"\u002Fzsxq",5,{"displayName":68,"href":72},[],{"displayName":77,"metadata":78,"spec":80,"status":83,"children":84},"特价云服务器",{"name":19,"creationTimestamp":79},"2026-09-25T15:30:59.201614Z",{"displayName":77,"href":81,"target":36,"priority":82,"menuName":8},"\u002Fserver",6,{"displayName":77,"href":81},[],{"metadata":86,"spec":89,"status":94,"postCount":96},{"name":87,"creationTimestamp":88},"mybatis-plus","2026-09-12T08:22:53.466780Z",{"displayName":90,"slug":87,"cover":91,"description":92,"priority":27,"hideFromList":93,"preventParentPostCascadeQuery":93},"MyBatis Plus 教程","\u002Fupload\u002Ftutorial-cover-mybatis-plus.png","MyBatis-Plus 从入门到实战：条件构造器、通用 CRUD、分页插件、代码生成与多租户。",false,{"permalink":95,"postCount":96,"visiblePostCount":96},"\u002Fcategories\u002Fmybatis-plus",18,[98,122,144,166,187,208,230,251,273,294,315,336,356,377,398,419,441,463],{"metadata":99,"spec":102,"status":113,"categories":117},{"name":100,"creationTimestamp":101},"post-mybatisplus-wrapper-condition-0f52be04","2026-09-12T08:30:08.659081Z",{"title":103,"slug":104,"cover":105,"excerpt":106,"publishTime":108,"categories":109,"tags":110,"priority":27,"pinned":93,"deleted":93,"visible":111,"allowComment":112},"Mybatis Plus Condition 详解（结合代码示例）","mybatisplus-wrapper-condition","\u002Fupload\u002F167344247547271-zSIv.jpg",{"raw":107,"autoGenerate":93},"前面小节中，我们已经学习了 Mybatis Plus 中使用频率超高的条件构造器，应该有会注意到很多方法中，都有一个 boolean 类型的 condition 字段，如下面的截图，这玩意到底是干嘛用的呢...","2026-09-12T08:30:08.716991Z",[87],[],"PUBLIC",true,{"permalink":114,"excerpt":107,"lastModifyTime":115,"phase":116},"\u002Farchives\u002Fmybatisplus-wrapper-condition","2026-09-13T05:25:08.061777Z","PUBLISHED",[118],{"metadata":119,"spec":120,"status":121,"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":123,"spec":126,"status":135,"categories":139},{"name":124,"creationTimestamp":125},"post-mybatisplus-quick-start-7438e7a7","2026-09-12T08:30:08.027221Z",{"title":127,"slug":128,"cover":129,"excerpt":130,"publishTime":132,"categories":133,"tags":134,"priority":27,"pinned":93,"deleted":93,"visible":111,"allowComment":112},"Mybatis Plus 快速开始","mybatisplus-quick-start","\u002Fupload\u002F164870371940555-tWiM.png",{"raw":131,"autoGenerate":93},"大家好，前面小节中，我们已经了解到什么是 Mybatis Plus， 以及和 Mybatis 的区别。本章节中，我们将上手学习如何使用它操作数据库...","2026-09-12T08:30:08.104840Z",[87],[],{"permalink":136,"excerpt":137,"lastModifyTime":138,"phase":116},"\u002Farchives\u002Fmybatisplus-quick-start","前面小节中，我们已经了解到什么是 Mybatis Plus， 以及和 Mybatis 的区别。本章节中，我们将上手学习如何使用它操作数据库...","2026-09-13T05:25:08.633120Z",[140],{"metadata":141,"spec":142,"status":143,"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":145,"spec":148,"status":157,"categories":161},{"name":146,"creationTimestamp":147},"post-mybatisplus-print-sql-6fd9382a","2026-09-12T08:30:07.357056Z",{"title":149,"slug":150,"cover":151,"excerpt":152,"publishTime":154,"categories":155,"tags":156,"priority":27,"pinned":93,"deleted":93,"visible":111,"allowComment":112},"Mybatis Plus 打印 SQL 语句（包含执行耗时）","mybatisplus-print-sql","\u002Fupload\u002F167091605638716-eGlp.jpg",{"raw":153,"autoGenerate":93},"大家好，项目中使用 Mybatis Plus 框架操作数据库时，如果是在本地开发（生产环境不推荐打印执行 SQL，会有数据泄漏风险），很希望完整的打印一下执行的 SQL，以及执行耗时，一方面可以方便调试，另一方面通过执行耗时，可以提醒我们改进一些慢 SQL...","2026-09-12T08:30:07.418896Z",[87],[],{"permalink":158,"excerpt":159,"lastModifyTime":160,"phase":116},"\u002Farchives\u002Fmybatisplus-print-sql","项目中使用 Mybatis Plus 框架操作数据库时，如果是在本地开发（生产环境不推荐打印执行 SQL，会有数据泄漏风险），很希望完整的打印一下执行的 SQL，以及执行耗时，一方面可以方便调试，另一方面通过执行耗时，可以提醒我们改进一些慢 SQL...","2026-09-13T05:25:11.894390Z",[162],{"metadata":163,"spec":164,"status":165,"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":167,"spec":170,"status":179,"categories":182},{"name":168,"creationTimestamp":169},"post-mybatisplus-page-query-cf6b396c","2026-09-12T08:30:06.634372Z",{"title":171,"slug":172,"cover":173,"excerpt":174,"publishTime":176,"categories":177,"tags":178,"priority":27,"pinned":93,"deleted":93,"visible":111,"allowComment":112},"Mybatis Plus 分页查询数据（图解）","mybatisplus-page-query","\u002Fupload\u002F167246380737773-bixm.jpg",{"raw":175,"autoGenerate":93},"本小节中，我们将学习如何通过 Mybatis Plus 分页查询数据库表中的数据。下图是我从京东上查询关键词「手机」 ，展示的手机数据就是分页查询，共有 91 页...","2026-09-12T08:30:06.704298Z",[87],[],{"permalink":180,"excerpt":175,"lastModifyTime":181,"phase":116},"\u002Farchives\u002Fmybatisplus-page-query","2026-09-13T05:25:14.891109Z",[183],{"metadata":184,"spec":185,"status":186,"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":188,"spec":191,"status":200,"categories":203},{"name":189,"creationTimestamp":190},"post-mybatisplus-optimistic-lock-ad7ba0dc","2026-09-12T08:30:05.848176Z",{"title":192,"slug":193,"cover":194,"excerpt":195,"publishTime":197,"categories":198,"tags":199,"priority":27,"pinned":93,"deleted":93,"visible":111,"allowComment":112},"Mybatis Plus 乐观锁插件（手把手教学）","mybatisplus-optimistic-lock","\u002Fupload\u002F167333816060936-YNck.jpg",{"raw":196,"autoGenerate":93},"程序设计中，若遇到高并发场景，需要多线程修改共享资源的时候，为了保证数据的原子性，就需要频繁使用到锁。锁的类型也有很多，如互斥锁、自旋锁、读写锁、悲观锁、乐观锁等，因为本文主要内容是 Mybatis Plus 实现乐观锁功能，就不展开讲了...","2026-09-12T08:30:05.904951Z",[87],[],{"permalink":201,"excerpt":196,"lastModifyTime":202,"phase":116},"\u002Farchives\u002Fmybatisplus-optimistic-lock","2026-09-13T05:25:15.535552Z",[204],{"metadata":205,"spec":206,"status":207,"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":209,"spec":212,"status":221,"categories":225},{"name":210,"creationTimestamp":211},"post-mybatisplus-insert-508e1eef","2026-09-12T08:30:05.087286Z",{"title":213,"slug":214,"cover":215,"excerpt":216,"publishTime":218,"categories":219,"tags":220,"priority":27,"pinned":93,"deleted":93,"visible":111,"allowComment":112},"Mybatis Plus 新增数据并返回主键 ID（图文讲解）","mybatisplus-insert","\u002Fupload\u002F167204808139593-dWMf.jpg",{"raw":217,"autoGenerate":93},"大家好，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。","2026-09-12T08:30:05.152745Z",[87],[],{"permalink":222,"excerpt":223,"lastModifyTime":224,"phase":116},"\u002Farchives\u002Fmybatisplus-insert","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。","2026-09-13T05:25:18.910864Z",[226],{"metadata":227,"spec":228,"status":229,"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":231,"spec":234,"status":243,"categories":246},{"name":232,"creationTimestamp":233},"post-mybatisplus-dynamic-table-name-2454e803","2026-09-12T08:30:04.221155Z",{"title":235,"slug":236,"cover":237,"excerpt":238,"publishTime":240,"categories":241,"tags":242,"priority":27,"pinned":93,"deleted":93,"visible":111,"allowComment":112},"Mybatis Plus 动态表名（图文讲解）","mybatisplus-dynamic-table-name","\u002Fupload\u002F167420281572597-bWCR.jpg",{"raw":239,"autoGenerate":93},"本小节中，我们将学习如何在 Mybatis Plus 中实现动态表名。啥是动态表名呢？我们都知道，当数据库单表存储数据太多时（比如单表超过 1000 万条数据），会严重影响查询效率，这就需要进行水平切分操作，将数据分别存储到不同表中...","2026-09-12T08:30:04.292849Z",[87],[],{"permalink":244,"excerpt":239,"lastModifyTime":245,"phase":116},"\u002Farchives\u002Fmybatisplus-dynamic-table-name","2026-09-13T05:25:20.735247Z",[247],{"metadata":248,"spec":249,"status":250,"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":252,"spec":255,"status":264,"categories":268},{"name":253,"creationTimestamp":254},"post-mybatisplus-delete-2134cc6a","2026-09-12T08:30:03.191339Z",{"title":256,"slug":257,"cover":258,"excerpt":259,"publishTime":261,"categories":262,"tags":263,"priority":27,"pinned":93,"deleted":93,"visible":111,"allowComment":112},"Mybatis Plus 删除数据（超详细）","mybatisplus-delete","\u002Fupload\u002F167214854711359-XVkX.jpg",{"raw":260,"autoGenerate":93},"大家好，本小节中，我们将学习如何通过 Mybatis Plus 删除数据库表中的数据。为了演示删除数据，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...","2026-09-12T08:30:03.250941Z",[87],[],{"permalink":265,"excerpt":266,"lastModifyTime":267,"phase":116},"\u002Farchives\u002Fmybatisplus-delete","本小节中，我们将学习如何通过 Mybatis Plus 删除数据库表中的数据。为了演示删除数据，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...","2026-09-13T05:25:21.767837Z",[269],{"metadata":270,"spec":271,"status":272,"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":274,"spec":277,"status":286,"categories":289},{"name":275,"creationTimestamp":276},"post-mybatisplus-batch-insert-0dfcd5a6","2026-09-12T08:30:02.464761Z",{"title":278,"slug":279,"cover":280,"excerpt":281,"publishTime":283,"categories":284,"tags":285,"priority":27,"pinned":93,"deleted":93,"visible":111,"allowComment":112},"Mybatis Plus 批量 Insert_新增数据（图文讲解）","mybatisplus-batch-insert","\u002Fupload\u002F167211863047181-DEdJ.jpg",{"raw":282,"autoGenerate":93},"本小节中，我们将学习如何通过 Mybatis Plus 实现 MySQL 批量插入数据。先抛出一个问题：假设老板给你下了个任务，向数据库中添加 100 万条数据，并且不能耗时太久...","2026-09-12T08:30:02.543036Z",[87],[],{"permalink":287,"excerpt":282,"lastModifyTime":288,"phase":116},"\u002Farchives\u002Fmybatisplus-batch-insert","2026-09-13T05:25:24.064210Z",[290],{"metadata":291,"spec":292,"status":293,"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":295,"spec":298,"status":307,"categories":310},{"name":296,"creationTimestamp":297},"post-mybatis-plus-integrate-0c3e6619","2026-09-12T08:30:01.532093Z",{"title":299,"slug":300,"cover":301,"excerpt":302,"publishTime":304,"categories":305,"tags":306,"priority":27,"pinned":93,"deleted":93,"visible":111,"allowComment":112},"Mybatis-Plus 整合集成","mybatis-plus-integrate","\u002Fupload\u002F164870378749787-sJrg.png",{"raw":303,"autoGenerate":93},"上小节中，我们学习了如何快速入门 Mybatis-Plus，文中以 Spring Boot + Maven 来讲解的，本文将详细的介绍如何在市面主流框架中整合&集成 Mybatis-Plus。","2026-09-12T08:30:01.743646Z",[87],[],{"permalink":308,"excerpt":303,"lastModifyTime":309,"phase":116},"\u002Farchives\u002Fmybatis-plus-integrate","2026-09-16T09:43:57.945654Z",[311],{"metadata":312,"spec":313,"status":314,"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":316,"spec":319,"status":328,"categories":331},{"name":317,"creationTimestamp":318},"post-mybaitsplus-wrapper-51f1c68c","2026-09-12T08:30:00.818539Z",{"title":320,"slug":321,"cover":322,"excerpt":323,"publishTime":325,"categories":326,"tags":327,"priority":27,"pinned":93,"deleted":93,"visible":111,"allowComment":112},"Mybatis Plus Wrapper 条件构造器（超详细）","mybaitsplus-wrapper","\u002Fupload\u002F167220794094570-TBuu.jpg",{"raw":324,"autoGenerate":93},"在 Mybatis 中，我们查询或者更新指定数据，可以直接在 xml 文件中写 SQL，然后通过占位符传入条件参数即可，比如你想根据用户 ID 去更新某个用户数据，那么 SQL 条件大致为 where id = #{id}...","2026-09-12T08:30:00.907062Z",[87],[],{"permalink":329,"excerpt":324,"lastModifyTime":330,"phase":116},"\u002Farchives\u002Fmybaitsplus-wrapper","2026-09-13T05:25:26.773490Z",[332],{"metadata":333,"spec":334,"status":335,"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":337,"spec":340,"status":348,"categories":351},{"name":338,"creationTimestamp":339},"post-mybaitsplus-update-7910a075","2026-09-12T08:30:00.045046Z",{"title":341,"slug":342,"cover":215,"excerpt":343,"publishTime":345,"categories":346,"tags":347,"priority":27,"pinned":93,"deleted":93,"visible":111,"allowComment":112},"Mybatis Plus 更新数据（图文讲解）","mybaitsplus-update",{"raw":344,"autoGenerate":93},"本小节中，我们将学习如何通过 Mybatis Plus 修改数据库表中的数据。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...","2026-09-12T08:30:00.114111Z",[87],[],{"permalink":349,"excerpt":344,"lastModifyTime":350,"phase":116},"\u002Farchives\u002Fmybaitsplus-update","2026-09-13T05:25:27.532631Z",[352],{"metadata":353,"spec":354,"status":355,"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":357,"spec":360,"status":369,"categories":372},{"name":358,"creationTimestamp":359},"post-mybaitsplus-select-data-bd965549","2026-09-12T08:29:59.301200Z",{"title":361,"slug":362,"cover":363,"excerpt":364,"publishTime":366,"categories":367,"tags":368,"priority":27,"pinned":93,"deleted":93,"visible":111,"allowComment":112},"Mybatis Plus 查询数据（图文讲解）","mybaitsplus-select-data","\u002Fupload\u002F167238066532413-dlWV.jpg",{"raw":365,"autoGenerate":93},"本小节中，我们将学习如何通过 Mybatis Plus 查询数据库表中的数据。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...","2026-09-12T08:29:59.380954Z",[87],[],{"permalink":370,"excerpt":365,"lastModifyTime":371,"phase":116},"\u002Farchives\u002Fmybaitsplus-select-data","2026-09-13T05:25:28.466672Z",[373],{"metadata":374,"spec":375,"status":376,"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":378,"spec":381,"status":390,"categories":393},{"name":379,"creationTimestamp":380},"post-mybaitsplus-logic-delete-22e24533","2026-09-12T08:29:58.277662Z",{"title":382,"slug":383,"cover":384,"excerpt":385,"publishTime":387,"categories":388,"tags":389,"priority":27,"pinned":93,"deleted":93,"visible":111,"allowComment":112},"Mybatis Plus 逻辑删除（手把手教学）","mybaitsplus-logic-delete","\u002Fupload\u002F167342448565316-QpIC.jpg",{"raw":386,"autoGenerate":93},"本小节中，我们将学习如何通过 Mybatis Plus 实现逻辑删除功能。讲逻辑删除之前，先说说物理删除。当我们想要删除数据库中的数据，都会执行一条 delete 语句，执行成功后...","2026-09-12T08:29:58.346883Z",[87],[],{"permalink":391,"excerpt":386,"lastModifyTime":392,"phase":116},"\u002Farchives\u002Fmybaitsplus-logic-delete","2026-09-13T05:25:29.585172Z",[394],{"metadata":395,"spec":396,"status":397,"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":399,"spec":402,"status":411,"categories":414},{"name":400,"creationTimestamp":401},"post-mybaitsplus-join-query-0b894da6","2026-09-12T08:29:57.423004Z",{"title":403,"slug":404,"cover":405,"excerpt":406,"publishTime":408,"categories":409,"tags":410,"priority":27,"pinned":93,"deleted":93,"visible":111,"allowComment":112},"Mybatis Plus 多表联查（包含分页关联查询,图文讲解）","mybaitsplus-join-query","\u002Fupload\u002F167273442141335-DKZI.jpg",{"raw":407,"autoGenerate":93},"本小节中，我们将学习如何通过 Mybatis Plus 实现多表关联查询，以及分页关联查询。本文以查询用户所下订单，来演示 Mybatis Plus 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":168,"creationTimestamp":169},{"title":171,"slug":172,"cover":173,"excerpt":487,"publishTime":176,"categories":488,"tags":489,"priority":27,"pinned":93,"deleted":93,"visible":111,"allowComment":112},{"raw":175,"autoGenerate":93},[87],[],{"permalink":180,"excerpt":175,"lastModifyTime":181,"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 分页查询数据库表中的数据。\u003C\u002Fp>\n\u003Ch2>什么是分页查询？\u003C\u002Fh2>\n\u003Cp>下图是从京东上查询关键词 \u003Cem>「手机」\u003C\u002Fem> ，展示的手机数据就是分页查询，共有 91 页：\u003C\u002Fp>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167246380737773-bixm.jpg\" loading=\"lazy\" title=\"京东商城的分页查询\" alt=\"京东商城的分页查询\">\u003Cspan class=\"image-caption\">京东商城的分页查询\u003C\u002Fspan>\n\u003C\u002Fp>\n\u003Cp>分页查询就是\u003Cstrong>把需要查询的数据集进行分批展示\u003C\u002Fstrong>，比如商品表中有 1万 条手机数据，每页按固定数量展示。\u003C\u002Fp>\n\u003Ch2>为什么需要分页查询？\u003C\u002Fh2>\n\u003Col>\n\u003Cli>\n\u003Cp>前端页面能够展示的内容有限；\u003C\u002Fp>\n\u003C\u002Fli>\n\u003Cli>\n\u003Cp>当数据库中数据量太多，比如 100W 条，一次性全部返回，查询速度慢，而且内存也顶不住；\u003C\u002Fp>\n\u003C\u002Fli>\n\u003C\u002Fol>\n\u003Ch2>表结构\u003C\u002Fh2>\n\u003Cp>了解到分页查询相关概念后，我们来上手 Mybatis Plus 的分页查询功能，还是之前小节中定义好的用户测试表， 执行脚本如下：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>DROP TABLE IF EXISTS user;\n\nCREATE TABLE `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>@TableName("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>不明白 Mybatis Plus 实体类注解的小伙伴，可参考前面小节\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>, 有详细解释。\u003C\u002Fp>\n\u003Ch2>新增测试数据\u003C\u002Fh2>\n\u003Cp>分页查询前，先通过代码插入一些测试数据，执行代码如下：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>\u002F\u002F 循环插入 100 条测试数据\nfor (int i = 0; i < 100; i++) {\n    User user = new User();\n    user.setName("张三" + i);\n    user.setAge(i);\n    user.setGender(1);\n\n    userMapper.insert(user);\n}\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cblockquote>\n\u003Cp>TIP : 不清楚如何插入数据可翻阅前面 《新增数据》\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> 小节；\u003C\u002Fp>\n\u003C\u002Fblockquote>\n\u003Ch2>添加分页插件\u003C\u002Fh2>\n\u003Cp>接着，在 \u003Ccode>MybatisPlusConfig\u003C\u002Fcode> 配置类中，添加分页插件 \u003Ccode>PaginationInnerInterceptor\u003C\u002Fcode>:\u003C\u002Fp>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167247912020155-YPWW.jpg\" loading=\"lazy\">\n\u003C\u002Fp>\n\u003Cpre>\u003Ccode>\u002F**\n * @Author: 张三\n * @Date: 2022-12-15 18:29\n * @Version: v1.0.0\n * @Description: TODO\n **\u002F\n@Configuration\n@MapperScan("com.mashangan.mybatisplusdemo.mapper")\npublic class MybatisPlusConfig {\n\n    \u002F**\n     * 分页插件\n     * @return\n     *\u002F\n    @Bean\n    public MybatisPlusInterceptor mybatisPlusInterceptor(){\n        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();\n        interceptor.addInnerInterceptor(new PaginationInnerInterceptor());\n        return interceptor;\n    }\n  \n}\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Ch2>开始分页查询数据\u003C\u002Fh2>\n\u003Cp>Mybatis Plus 对 Mapper 层和 Service 层都将常见的增删改查操作封装好了，只需简单的继承，即可轻松搞定对数据的增删改查，本文重点讲解分页查询相关的部分。\u003C\u002Fp>\n\u003Ch3>Mapper 层\u003C\u002Fh3>\n\u003Cp>定义一个 \u003Ccode>UserMapper\u003C\u002Fcode> , 让其继承自 \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> 提供的分页查询相关的方法如下：\u003C\u002Fp>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167246462284126-HAVn.jpg\" loading=\"lazy\">\n\u003C\u002Fp>\n\u003Cp>解释一下每个方法的作用：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>\u002F\u002F 分页查询，page 用于设置需要查询的页数，以及每页展示数据量，wrapper 用于组装查询条件\nIPage<T> selectPage(IPage<T> page, Wrapper<T> queryWrapper);\n\u002F\u002F 同上，区别是用 map 来接受查询的数据\nIPage<Map<String, Object>> selectMapsPage(IPage<T> page, Wrapper<T> queryWrapper);\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>参数说明：\u003C\u002Fp>\n\u003Ctable>\n\u003Cthead>\n\u003Ctr>\n\u003Cth align=\"center\">类型\u003C\u002Fth>\n\u003Cth align=\"center\">参数名\u003C\u002Fth>\n\u003Cth align=\"center\">描述\u003C\u002Fth>\n\u003C\u002Ftr>\n\u003C\u002Fthead>\n\u003Ctbody>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>Wrapper<T>\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>queryWrapper\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">实体对象封装操作类（可以为 \u003Ccode>null\u003C\u002Fcode>）\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>IPage<T>\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>page\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">分页查询条件（可以为 \u003Ccode>RowBounds.DEFAULT\u003C\u002Fcode>）\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003C\u002Ftbody>\n\u003C\u002Ftable>\n\u003Ch4>示例代码\u003C\u002Fh4>\n\u003Cp>接下来，本文来演示一些示例代码以便你快速了解如何使用分页查询：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>\u002F\u002F 组装查询条件\nQueryWrapper<User> queryWrapper = new QueryWrapper<>();\n\u002F\u002F where age = 30\nqueryWrapper.eq("age", 30);\n\n\u002F\u002F 查询第 2 页数据，每页 10 条\nPage<User> page = new Page<>(2, 10);\n\npage = userMapper.selectPage(page, queryWrapper);\nSystem.out.println("总记录数：" + page.getTotal());\nSystem.out.println("总共多少页：" + page.getPages());\nSystem.out.println("当前页码：" + page.getCurrent());\n\u002F\u002F 当前页数据\nList<User> users = page.getRecords();\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>执行上面的代码，实际上执行了两条 SQL ： 先执行 \u003Ccode>COUNT(*)\u003C\u002Fcode> 查询出记录总数，然后才是分页语句 \u003Ccode>LIMIT\u003C\u002Fcode>:\u003C\u002Fp>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167248872739375-JHcV.jpg\" loading=\"lazy\">\n\u003C\u002Fp>\n\u003Ch5>Page 类说明\u003C\u002Fh5>\n\u003Cblockquote>\n\u003Cp>该类继承了 \u003Ccode>IPage\u003C\u002Fcode> 类，实现了 \u003Cem>简单分页模型\u003C\u002Fem> ，如果你要实现自己的分页模型可以继承 \u003Ccode>Page\u003C\u002Fcode> 类或者实现 \u003Ccode>IPage\u003C\u002Fcode> 类\u003C\u002Fp>\n\u003C\u002Fblockquote>\n\u003Ctable>\n\u003Cthead>\n\u003Ctr>\n\u003Cth align=\"center\">属性名\u003C\u002Fth>\n\u003Cth align=\"center\">类型\u003C\u002Fth>\n\u003Cth align=\"center\">默认值\u003C\u002Fth>\n\u003Cth align=\"center\">描述\u003C\u002Fth>\n\u003C\u002Ftr>\n\u003C\u002Fthead>\n\u003Ctbody>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>records\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>List\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>emptyList\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">查询数据列表\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>total\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>Long\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">0\u003C\u002Ftd>\n\u003Ctd align=\"center\">查询列表总记录数\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>size\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>Long\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">10\u003C\u002Ftd>\n\u003Ctd align=\"center\">每页显示条数，默认 \u003Ccode>10\u003C\u002Fcode>\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>current\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>Long\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">1\u003C\u002Ftd>\n\u003Ctd align=\"center\">当前页\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>orders\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>List\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>emptyList\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">排序字段信息，允许前端传入的时候，注意 SQL 注入问题，可以使用 \u003Ccode>SqlInjectionUtils.check(...)\u003C\u002Fcode> 检查文本\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>optimizeCountSql\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>boolean\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>true\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">自动优化 COUNT SQL 如果遇到 \u003Ccode>jSqlParser\u003C\u002Fcode> 无法解析情况，设置该参数为 \u003Ccode>false\u003C\u002Fcode>\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>optimizeJoinOfCountSql\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>boolean\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>true\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">自动优化 \u003Ccode>COUNT SQL\u003C\u002Fcode> 是否把 \u003Ccode>join\u003C\u002Fcode> 查询部分移除\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>searchCount\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>boolean\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>true\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">是否进行 count 查询，如果指向查询到列表不要查询总记录数，设置该参数为 \u003Ccode>false\u003C\u002Fcode>\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>maxLimit\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>Long\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003C\u002Ftd>\n\u003Ctd align=\"center\">单页分页条数限制\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>countId\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>String\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>xml\u003C\u002Fcode> 自定义 \u003Ccode>count\u003C\u002Fcode> 查询的 \u003Ccode>statementId\u003C\u002Fcode>\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003C\u002Ftbody>\n\u003C\u002Ftable>\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>Service 层封装的分页相关方法如下：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>\u002F\u002F 无条件分页查询\nIPage<T> page(IPage<T> page);\n\u002F\u002F 条件分页查询\nIPage<T> page(IPage<T> page, Wrapper<T> queryWrapper);\n\u002F\u002F 无条件分页查询\nIPage<Map<String, Object>> pageMaps(IPage<T> page);\n\u002F\u002F 条件分页查询\nIPage<Map<String, Object>> pageMaps(IPage<T> page, Wrapper<T> queryWrapper);\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Ch4>示例代码\u003C\u002Fh4>\n\u003Cp>Service 层的分页方法入参和 Mapper 差不多：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>\u002F\u002F 组装查询条件\nQueryWrapper<User> queryWrapper = new QueryWrapper<>();\n\u002F\u002F where age = 30\nqueryWrapper.eq("age", 30);\n\n\u002F\u002F 查询第 2 页数据，每页 10 条\nPage<User> page = new Page<>(2, 10);\n\npage = userService.page(page, queryWrapper);\nSystem.out.println("总记录数：" + page.getTotal());\nSystem.out.println("总共多少页：" + page.getPages());\nSystem.out.println("当前页码：" + page.getCurrent());\n\u002F\u002F 当前页数据\nList<User> users = page.getRecords();\n\u003C\u002Fcode>\u003C\u002Fpre>\n15:T9a49,\u003Cp>\u003C\u002Fp>\n\u003Cp>本小节中，我们将学习如何通过 Mybatis Plus 分页查询数据库表中的数据。\u003C\u002Fp>\n\u003Ch2 id=\"toc-0\">什么是分页查询？\u003C\u002Fh2>\n\u003Cp>下图是从京东上查询关键词 \u003Cem>「手机」\u003C\u002Fem> ，展示的手机数据就是分页查询，共有 91 页：\u003C\u002Fp>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167246380737773-bixm.jpg\" loading=\"lazy\" title=\"京东商城的分页查询\" alt=\"京东商城的分页查询\">\u003C\u002Fdiv>\u003Cspan class=\"image-caption\">京东商城的分页查询\u003C\u002Fspan>\n\u003C\u002Fp>\n\u003Cp>分页查询就是\u003Cstrong>把需要查询的数据集进行分批展示\u003C\u002Fstrong>，比如商品表中有 1万 条手机数据，每页按固定数量展示。\u003C\u002Fp>\n\u003Ch2 id=\"toc-1\">为什么需要分页查询？\u003C\u002Fh2>\n\u003Col>\n\u003Cli>\n\u003Cp>前端页面能够展示的内容有限；\u003C\u002Fp>\n\u003C\u002Fli>\n\u003Cli>\n\u003Cp>当数据库中数据量太多，比如 100W 条，一次性全部返回，查询速度慢，而且内存也顶不住；\u003C\u002Fp>\n\u003C\u002Fli>\n\u003C\u002Fol>\n\u003Ch2 id=\"toc-2\">表结构\u003C\u002Fh2>\n\u003Cp>了解到分页查询相关概念后，我们来上手 Mybatis Plus 的分页查询功能，还是之前小节中定义好的用户测试表， 执行脚本如下：\u003C\u002Fp>\n\u003Cdiv class=\"language-sql\" data-ext=\"sql\" data-code=\"DROP%20TABLE%20IF%20EXISTS%20user%3B%0A%0ACREATE%20TABLE%20%60user%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> \u003Cspan class=\"token keyword\">user\u003C\u002Fspan>\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>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-3\">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=\"%40TableName(%22user%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\">@TableName\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token string\">\"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>不明白 Mybatis Plus 实体类注解的小伙伴，可参考前面小节\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>, 有详细解释。\u003C\u002Fp>\n\u003Ch2 id=\"toc-4\">新增测试数据\u003C\u002Fh2>\n\u003Cp>分页查询前，先通过代码插入一些测试数据，执行代码如下：\u003C\u002Fp>\n\u003Cdiv class=\"language-dockerfile\" data-ext=\"dockerfile\" data-code=\"%2F%2F%20%E5%BE%AA%E7%8E%AF%E6%8F%92%E5%85%A5%20100%20%E6%9D%A1%E6%B5%8B%E8%AF%95%E6%95%B0%E6%8D%AE%0Afor%20(int%20i%20%3D%200%3B%20i%20%3C%20100%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%0A%20%20%20%20userMapper.insert(user)%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-dockerfile\">\u002F\u002F 循环插入 100 条测试数据\nfor (int i = 0; i < 100; 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\n    userMapper.insert(user);\n}\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cblockquote>\n\u003Cp>TIP : 不清楚如何插入数据可翻阅前面 《新增数据》\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> 小节；\u003C\u002Fp>\n\u003C\u002Fblockquote>\n\u003Ch2 id=\"toc-5\">添加分页插件\u003C\u002Fh2>\n\u003Cp>接着，在 \u003Ccode>MybatisPlusConfig\u003C\u002Fcode> 配置类中，添加分页插件 \u003Ccode>PaginationInnerInterceptor\u003C\u002Fcode>:\u003C\u002Fp>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167247912020155-YPWW.jpg\" loading=\"lazy\">\u003C\u002Fdiv>\n\u003C\u002Fp>\n\u003Cdiv class=\"language-java\" data-ext=\"java\" data-code=\"%2F**%0A%20*%20%40Author%3A%20%E5%BC%A0%E4%B8%89%0A%20*%20%40From%3A%20%E5%85%AC%E4%BC%97%E5%8F%B7%EF%BC%9A%E5%BC%A0%E4%B8%89%2C%20%E7%BD%91%E7%AB%99%EF%BC%9Awww.mashangan.com%0A%20*%20%40Date%3A%202022-12-15%2018%3A29%0A%20*%20%40Version%3A%20v1.0.0%0A%20*%20%40Description%3A%20TODO%0A%20**%2F%0A%40Configuration%0A%40MapperScan(%22com.mashangan.mybatisplusdemo.mapper%22)%0Apublic%20class%20MybatisPlusConfig%20%7B%0A%0A%20%20%20%20%2F**%0A%20%20%20%20%20*%20%E5%88%86%E9%A1%B5%E6%8F%92%E4%BB%B6%0A%20%20%20%20%20*%20%40return%0A%20%20%20%20%20*%2F%0A%20%20%20%20%40Bean%0A%20%20%20%20public%20MybatisPlusInterceptor%20mybatisPlusInterceptor()%7B%0A%20%20%20%20%20%20%20%20MybatisPlusInterceptor%20interceptor%20%3D%20new%20MybatisPlusInterceptor()%3B%0A%20%20%20%20%20%20%20%20interceptor.addInnerInterceptor(new%20PaginationInnerInterceptor())%3B%0A%20%20%20%20%20%20%20%20return%20interceptor%3B%0A%20%20%20%20%7D%0A%20%20%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 comment\">\u002F**\n * @Author: 张三\n * @Date: 2022-12-15 18:29\n * @Version: v1.0.0\n * @Description: TODO\n **\u002F\u003C\u002Fspan>\n\u003Cspan class=\"token annotation punctuation\">@Configuration\u003C\u002Fspan>\n\u003Cspan class=\"token annotation punctuation\">@MapperScan\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token string\">\"com.mashangan.mybatisplusdemo.mapper\"\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\">MybatisPlusConfig\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">{\u003C\u002Fspan>\n\n    \u003Cspan class=\"token comment\">\u002F**\n     * 分页插件\n     * @return\n     *\u002F\u003C\u002Fspan>\n    \u003Cspan class=\"token annotation punctuation\">@Bean\u003C\u002Fspan>\n    \u003Cspan class=\"token keyword\">public\u003C\u002Fspan> \u003Cspan class=\"token class-name\">MybatisPlusInterceptor\u003C\u002Fspan> \u003Cspan class=\"token function\">mybatisPlusInterceptor\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">{\u003C\u002Fspan>\n        \u003Cspan class=\"token class-name\">MybatisPlusInterceptor\u003C\u002Fspan> interceptor \u003Cspan class=\"token operator\">=\u003C\u002Fspan> \u003Cspan class=\"token keyword\">new\u003C\u002Fspan> \u003Cspan class=\"token class-name\">MybatisPlusInterceptor\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n        interceptor\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">addInnerInterceptor\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token keyword\">new\u003C\u002Fspan> \u003Cspan class=\"token class-name\">PaginationInnerInterceptor\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\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\">return\u003C\u002Fspan> interceptor\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n    \u003Cspan class=\"token punctuation\">}\u003C\u002Fspan>\n  \n\u003Cspan class=\"token punctuation\">}\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Ch2 id=\"toc-6\">开始分页查询数据\u003C\u002Fh2>\n\u003Cp>Mybatis Plus 对 Mapper 层和 Service 层都将常见的增删改查操作封装好了，只需简单的继承，即可轻松搞定对数据的增删改查，本文重点讲解分页查询相关的部分。\u003C\u002Fp>\n\u003Ch3 id=\"toc-7\">Mapper 层\u003C\u002Fh3>\n\u003Cp>定义一个 \u003Ccode>UserMapper\u003C\u002Fcode> , 让其继承自 \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> 提供的分页查询相关的方法如下：\u003C\u002Fp>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167246462284126-HAVn.jpg\" loading=\"lazy\">\u003C\u002Fdiv>\n\u003C\u002Fp>\n\u003Cp>解释一下每个方法的作用：\u003C\u002Fp>\n\u003Cdiv class=\"language-xml\" data-ext=\"xml\" data-code=\"%2F%2F%20%E5%88%86%E9%A1%B5%E6%9F%A5%E8%AF%A2%EF%BC%8Cpage%20%E7%94%A8%E4%BA%8E%E8%AE%BE%E7%BD%AE%E9%9C%80%E8%A6%81%E6%9F%A5%E8%AF%A2%E7%9A%84%E9%A1%B5%E6%95%B0%EF%BC%8C%E4%BB%A5%E5%8F%8A%E6%AF%8F%E9%A1%B5%E5%B1%95%E7%A4%BA%E6%95%B0%E6%8D%AE%E9%87%8F%EF%BC%8Cwrapper%20%E7%94%A8%E4%BA%8E%E7%BB%84%E8%A3%85%E6%9F%A5%E8%AF%A2%E6%9D%A1%E4%BB%B6%0AIPage%3CT%3E%20selectPage(IPage%3CT%3E%20page%2C%20Wrapper%3CT%3E%20queryWrapper)%3B%0A%2F%2F%20%E5%90%8C%E4%B8%8A%EF%BC%8C%E5%8C%BA%E5%88%AB%E6%98%AF%E7%94%A8%20map%20%E6%9D%A5%E6%8E%A5%E5%8F%97%E6%9F%A5%E8%AF%A2%E7%9A%84%E6%95%B0%E6%8D%AE%0AIPage%3CMap%3CString%2C%20Object%3E%3E%20selectMapsPage(IPage%3CT%3E%20page%2C%20Wrapper%3CT%3E%20queryWrapper)%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-xml\">\u002F\u002F 分页查询，page 用于设置需要查询的页数，以及每页展示数据量，wrapper 用于组装查询条件\nIPage\u003Cspan class=\"token tag\">\u003Cspan class=\"token tag\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>T\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> selectPage(IPage\u003Cspan class=\"token tag\">\u003Cspan class=\"token tag\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>T\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> page, Wrapper\u003Cspan class=\"token tag\">\u003Cspan class=\"token tag\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>T\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> queryWrapper);\n\u002F\u002F 同上，区别是用 map 来接受查询的数据\nIPage<Map\u003Cspan class=\"token tag\">\u003Cspan class=\"token tag\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>String,\u003C\u002Fspan> \u003Cspan class=\"token attr-name\">Object\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan>> selectMapsPage(IPage\u003Cspan class=\"token tag\">\u003Cspan class=\"token tag\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>T\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> page, Wrapper\u003Cspan class=\"token tag\">\u003Cspan class=\"token tag\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>T\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> queryWrapper);\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>参数说明：\u003C\u002Fp>\n\u003Ctable>\n\u003Cthead>\n\u003Ctr>\n\u003Cth align=\"center\">类型\u003C\u002Fth>\n\u003Cth align=\"center\">参数名\u003C\u002Fth>\n\u003Cth align=\"center\">描述\u003C\u002Fth>\n\u003C\u002Ftr>\n\u003C\u002Fthead>\n\u003Ctbody>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>Wrapper<T>\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>queryWrapper\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">实体对象封装操作类（可以为 \u003Ccode>null\u003C\u002Fcode>）\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>IPage<T>\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>page\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">分页查询条件（可以为 \u003Ccode>RowBounds.DEFAULT\u003C\u002Fcode>）\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003C\u002Ftbody>\n\u003C\u002Ftable>\n\u003Ch4 id=\"toc-8\">示例代码\u003C\u002Fh4>\n\u003Cp>接下来，本文来演示一些示例代码以便你快速了解如何使用分页查询：\u003C\u002Fp>\n\u003Cdiv class=\"language-java\" data-ext=\"java\" data-code=\"%2F%2F%20%E7%BB%84%E8%A3%85%E6%9F%A5%E8%AF%A2%E6%9D%A1%E4%BB%B6%0AQueryWrapper%3CUser%3E%20queryWrapper%20%3D%20new%20QueryWrapper%3C%3E()%3B%0A%2F%2F%20where%20age%20%3D%2030%0AqueryWrapper.eq(%22age%22%2C%2030)%3B%0A%0A%2F%2F%20%E6%9F%A5%E8%AF%A2%E7%AC%AC%202%20%E9%A1%B5%E6%95%B0%E6%8D%AE%EF%BC%8C%E6%AF%8F%E9%A1%B5%2010%20%E6%9D%A1%0APage%3CUser%3E%20page%20%3D%20new%20Page%3C%3E(2%2C%2010)%3B%0A%0Apage%20%3D%20userMapper.selectPage(page%2C%20queryWrapper)%3B%0ASystem.out.println(%22%E6%80%BB%E8%AE%B0%E5%BD%95%E6%95%B0%EF%BC%9A%22%20%2B%20page.getTotal())%3B%0ASystem.out.println(%22%E6%80%BB%E5%85%B1%E5%A4%9A%E5%B0%91%E9%A1%B5%EF%BC%9A%22%20%2B%20page.getPages())%3B%0ASystem.out.println(%22%E5%BD%93%E5%89%8D%E9%A1%B5%E7%A0%81%EF%BC%9A%22%20%2B%20page.getCurrent())%3B%0A%2F%2F%20%E5%BD%93%E5%89%8D%E9%A1%B5%E6%95%B0%E6%8D%AE%0AList%3CUser%3E%20users%20%3D%20page.getRecords()%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 comment\">\u002F\u002F 组装查询条件\u003C\u002Fspan>\n\u003Cspan class=\"token class-name\">QueryWrapper\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> queryWrapper \u003Cspan class=\"token operator\">=\u003C\u002Fspan> \u003Cspan class=\"token keyword\">new\u003C\u002Fspan> \u003Cspan class=\"token class-name\">QueryWrapper\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\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 where age = 30\u003C\u002Fspan>\nqueryWrapper\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">eq\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token string\">\"age\"\u003C\u002Fspan>\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\n\u003Cspan class=\"token comment\">\u002F\u002F 查询第 2 页数据，每页 10 条\u003C\u002Fspan>\n\u003Cspan class=\"token class-name\">Page\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> page \u003Cspan class=\"token operator\">=\u003C\u002Fspan> \u003Cspan class=\"token keyword\">new\u003C\u002Fspan> \u003Cspan class=\"token class-name\">Page\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token number\">2\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token number\">10\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\npage \u003Cspan class=\"token operator\">=\u003C\u002Fspan> userMapper\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">selectPage\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>page\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> queryWrapper\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token class-name\">System\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>out\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">println\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token string\">\"总记录数：\"\u003C\u002Fspan> \u003Cspan class=\"token operator\">+\u003C\u002Fspan> page\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">getTotal\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token class-name\">System\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>out\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">println\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token string\">\"总共多少页：\"\u003C\u002Fspan> \u003Cspan class=\"token operator\">+\u003C\u002Fspan> page\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">getPages\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token class-name\">System\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>out\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">println\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token string\">\"当前页码：\"\u003C\u002Fspan> \u003Cspan class=\"token operator\">+\u003C\u002Fspan> page\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">getCurrent\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\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 当前页数据\u003C\u002Fspan>\n\u003Cspan class=\"token class-name\">List\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> users \u003Cspan class=\"token operator\">=\u003C\u002Fspan> page\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">getRecords\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>执行上面的代码，实际上执行了两条 SQL ： 先执行 \u003Ccode>COUNT(*)\u003C\u002Fcode> 查询出记录总数，然后才是分页语句 \u003Ccode>LIMIT\u003C\u002Fcode>:\u003C\u002Fp>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167248872739375-JHcV.jpg\" loading=\"lazy\">\u003C\u002Fdiv>\n\u003C\u002Fp>\n\u003Ch5 id=\"toc-9\">Page 类说明\u003C\u002Fh5>\n\u003Cblockquote>\n\u003Cp>该类继承了 \u003Ccode>IPage\u003C\u002Fcode> 类，实现了 \u003Cem>简单分页模型\u003C\u002Fem> ，如果你要实现自己的分页模型可以继承 \u003Ccode>Page\u003C\u002Fcode> 类或者实现 \u003Ccode>IPage\u003C\u002Fcode> 类\u003C\u002Fp>\n\u003C\u002Fblockquote>\n\u003Ctable>\n\u003Cthead>\n\u003Ctr>\n\u003Cth align=\"center\">属性名\u003C\u002Fth>\n\u003Cth align=\"center\">类型\u003C\u002Fth>\n\u003Cth align=\"center\">默认值\u003C\u002Fth>\n\u003Cth align=\"center\">描述\u003C\u002Fth>\n\u003C\u002Ftr>\n\u003C\u002Fthead>\n\u003Ctbody>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>records\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>List\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>emptyList\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">查询数据列表\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>total\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>Long\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">0\u003C\u002Ftd>\n\u003Ctd align=\"center\">查询列表总记录数\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>size\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>Long\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">10\u003C\u002Ftd>\n\u003Ctd align=\"center\">每页显示条数，默认 \u003Ccode>10\u003C\u002Fcode>\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>current\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>Long\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">1\u003C\u002Ftd>\n\u003Ctd align=\"center\">当前页\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>orders\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>List\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>emptyList\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">排序字段信息，允许前端传入的时候，注意 SQL 注入问题，可以使用 \u003Ccode>SqlInjectionUtils.check(...)\u003C\u002Fcode> 检查文本\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>optimizeCountSql\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>boolean\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>true\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">自动优化 COUNT SQL 如果遇到 \u003Ccode>jSqlParser\u003C\u002Fcode> 无法解析情况，设置该参数为 \u003Ccode>false\u003C\u002Fcode>\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>optimizeJoinOfCountSql\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>boolean\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>true\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">自动优化 \u003Ccode>COUNT SQL\u003C\u002Fcode> 是否把 \u003Ccode>join\u003C\u002Fcode> 查询部分移除\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>searchCount\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>boolean\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>true\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">是否进行 count 查询，如果指向查询到列表不要查询总记录数，设置该参数为 \u003Ccode>false\u003C\u002Fcode>\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>maxLimit\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>Long\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003C\u002Ftd>\n\u003Ctd align=\"center\">单页分页条数限制\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>countId\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>String\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>xml\u003C\u002Fcode> 自定义 \u003Ccode>count\u003C\u002Fcode> 查询的 \u003Ccode>statementId\u003C\u002Fcode>\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003C\u002Ftbody>\n\u003C\u002Ftable>\n\u003Ch3 id=\"toc-10\">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>Service 层封装的分页相关方法如下：\u003C\u002Fp>\n\u003Cdiv class=\"language-javascript\" data-ext=\"javascript\" data-code=\"%2F%2F%20%E6%97%A0%E6%9D%A1%E4%BB%B6%E5%88%86%E9%A1%B5%E6%9F%A5%E8%AF%A2%0AIPage%3CT%3E%20page(IPage%3CT%3E%20page)%3B%0A%2F%2F%20%E6%9D%A1%E4%BB%B6%E5%88%86%E9%A1%B5%E6%9F%A5%E8%AF%A2%0AIPage%3CT%3E%20page(IPage%3CT%3E%20page%2C%20Wrapper%3CT%3E%20queryWrapper)%3B%0A%2F%2F%20%E6%97%A0%E6%9D%A1%E4%BB%B6%E5%88%86%E9%A1%B5%E6%9F%A5%E8%AF%A2%0AIPage%3CMap%3CString%2C%20Object%3E%3E%20pageMaps(IPage%3CT%3E%20page)%3B%0A%2F%2F%20%E6%9D%A1%E4%BB%B6%E5%88%86%E9%A1%B5%E6%9F%A5%E8%AF%A2%0AIPage%3CMap%3CString%2C%20Object%3E%3E%20pageMaps(IPage%3CT%3E%20page%2C%20Wrapper%3CT%3E%20queryWrapper)%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-javascript\">\u003Cspan class=\"token comment\">\u002F\u002F 无条件分页查询\u003C\u002Fspan>\nIPage\u003Cspan class=\"token operator\"><\u003C\u002Fspan>\u003Cspan class=\"token constant\">T\u003C\u002Fspan>\u003Cspan class=\"token operator\">>\u003C\u002Fspan> \u003Cspan class=\"token function\">page\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>IPage\u003Cspan class=\"token operator\"><\u003C\u002Fspan>\u003Cspan class=\"token constant\">T\u003C\u002Fspan>\u003Cspan class=\"token operator\">>\u003C\u002Fspan> page\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token comment\">\u002F\u002F 条件分页查询\u003C\u002Fspan>\nIPage\u003Cspan class=\"token operator\"><\u003C\u002Fspan>\u003Cspan class=\"token constant\">T\u003C\u002Fspan>\u003Cspan class=\"token operator\">>\u003C\u002Fspan> \u003Cspan class=\"token function\">page\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>IPage\u003Cspan class=\"token operator\"><\u003C\u002Fspan>\u003Cspan class=\"token constant\">T\u003C\u002Fspan>\u003Cspan class=\"token operator\">>\u003C\u002Fspan> page\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> Wrapper\u003Cspan class=\"token operator\"><\u003C\u002Fspan>\u003Cspan class=\"token constant\">T\u003C\u002Fspan>\u003Cspan class=\"token operator\">>\u003C\u002Fspan> queryWrapper\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token comment\">\u002F\u002F 无条件分页查询\u003C\u002Fspan>\nIPage\u003Cspan class=\"token operator\"><\u003C\u002Fspan>Map\u003Cspan class=\"token operator\"><\u003C\u002Fspan>String\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> Object\u003Cspan class=\"token operator\">>>\u003C\u002Fspan> \u003Cspan class=\"token function\">pageMaps\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>IPage\u003Cspan class=\"token operator\"><\u003C\u002Fspan>\u003Cspan class=\"token constant\">T\u003C\u002Fspan>\u003Cspan class=\"token operator\">>\u003C\u002Fspan> page\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token comment\">\u002F\u002F 条件分页查询\u003C\u002Fspan>\nIPage\u003Cspan class=\"token operator\"><\u003C\u002Fspan>Map\u003Cspan class=\"token operator\"><\u003C\u002Fspan>String\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> Object\u003Cspan class=\"token operator\">>>\u003C\u002Fspan> \u003Cspan class=\"token function\">pageMaps\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>IPage\u003Cspan class=\"token operator\"><\u003C\u002Fspan>\u003Cspan class=\"token constant\">T\u003C\u002Fspan>\u003Cspan class=\"token operator\">>\u003C\u002Fspan> page\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> Wrapper\u003Cspan class=\"token operator\"><\u003C\u002Fspan>\u003Cspan class=\"token constant\">T\u003C\u002Fspan>\u003Cspan class=\"token operator\">>\u003C\u002Fspan> queryWrapper\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Ch4 id=\"toc-11\">示例代码\u003C\u002Fh4>\n\u003Cp>Service 层的分页方法入参和 Mapper 差不多：\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 分页查询数据库表中的数据。\u003C\u002Fp>\n\u003Ch2>什么是分页查询？\u003C\u002Fh2>\n\u003Cp>下图是从京东上查询关键词 \u003Cem>「手机」\u003C\u002Fem> ，展示的手机数据就是分页查询，共有 91 页：\u003C\u002Fp>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167246380737773-bixm.jpg\" loading=\"lazy\" title=\"京东商城的分页查询\" alt=\"京东商城的分页查询\">\u003Cspan class=\"image-caption\">京东商城的分页查询\u003C\u002Fspan>\n\u003C\u002Fp>\n\u003Cp>分页查询就是\u003Cstrong>把需要查询的数据集进行分批展示\u003C\u002Fstrong>，比如商品表中有 1万 条手机数据，每页按固定数量展示。\u003C\u002Fp>\n\u003Ch2>为什么需要分页查询？\u003C\u002Fh2>\n\u003Col>\n\u003Cli>\n\u003Cp>前端页面能够展示的内容有限；\u003C\u002Fp>\n\u003C\u002Fli>\n\u003Cli>\n\u003Cp>当数据库中数据量太多，比如 100W 条，一次性全部返回，查询速度慢，而且内存也顶不住；\u003C\u002Fp>\n\u003C\u002Fli>\n\u003C\u002Fol>\n\u003Ch2>表结构\u003C\u002Fh2>\n\u003Cp>了解到分页查询相关概念后，我们来上手 Mybatis Plus 的分页查询功能，还是之前小节中定义好的用户测试表， 执行脚本如下：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>DROP TABLE IF EXISTS user;\n\nCREATE TABLE `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>@TableName("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>不明白 Mybatis Plus 实体类注解的小伙伴，可参考前面小节\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>, 有详细解释。\u003C\u002Fp>\n\u003Ch2>新增测试数据\u003C\u002Fh2>\n\u003Cp>分页查询前，先通过代码插入一些测试数据，执行代码如下：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>\u002F\u002F 循环插入 100 条测试数据\nfor (int i = 0; i < 100; i++) {\n    User user = new User();\n    user.setName("张三" + i);\n    user.setAge(i);\n    user.setGender(1);\n\n    userMapper.insert(user);\n}\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cblockquote>\n\u003Cp>TIP : 不清楚如何插入数据可翻阅前面 《新增数据》\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> 小节；\u003C\u002Fp>\n\u003C\u002Fblockquote>\n\u003Ch2>添加分页插件\u003C\u002Fh2>\n\u003Cp>接着，在 \u003Ccode>MybatisPlusConfig\u003C\u002Fcode> 配置类中，添加分页插件 \u003Ccode>PaginationInnerInterceptor\u003C\u002Fcode>:\u003C\u002Fp>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167247912020155-YPWW.jpg\" loading=\"lazy\">\n\u003C\u002Fp>\n\u003Cpre>\u003Ccode>\u002F**\n * @Author: 张三\n * @Date: 2022-12-15 18:29\n * @Version: v1.0.0\n * @Description: TODO\n **\u002F\n@Configuration\n@MapperScan("com.mashangan.mybatisplusdemo.mapper")\npublic class MybatisPlusConfig {\n\n    \u002F**\n     * 分页插件\n     * @return\n     *\u002F\n    @Bean\n    public MybatisPlusInterceptor mybatisPlusInterceptor(){\n        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();\n        interceptor.addInnerInterceptor(new PaginationInnerInterceptor());\n        return interceptor;\n    }\n  \n}\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Ch2>开始分页查询数据\u003C\u002Fh2>\n\u003Cp>Mybatis Plus 对 Mapper 层和 Service 层都将常见的增删改查操作封装好了，只需简单的继承，即可轻松搞定对数据的增删改查，本文重点讲解分页查询相关的部分。\u003C\u002Fp>\n\u003Ch3>Mapper 层\u003C\u002Fh3>\n\u003Cp>定义一个 \u003Ccode>UserMapper\u003C\u002Fcode> , 让其继承自 \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> 提供的分页查询相关的方法如下：\u003C\u002Fp>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167246462284126-HAVn.jpg\" loading=\"lazy\">\n\u003C\u002Fp>\n\u003Cp>解释一下每个方法的作用：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>\u002F\u002F 分页查询，page 用于设置需要查询的页数，以及每页展示数据量，wrapper 用于组装查询条件\nIPage<T> selectPage(IPage<T> page, Wrapper<T> queryWrapper);\n\u002F\u002F 同上，区别是用 map 来接受查询的数据\nIPage<Map<String, Object>> selectMapsPage(IPage<T> page, Wrapper<T> queryWrapper);\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>参数说明：\u003C\u002Fp>\n\u003Ctable>\n\u003Cthead>\n\u003Ctr>\n\u003Cth align=\"center\">类型\u003C\u002Fth>\n\u003Cth align=\"center\">参数名\u003C\u002Fth>\n\u003Cth align=\"center\">描述\u003C\u002Fth>\n\u003C\u002Ftr>\n\u003C\u002Fthead>\n\u003Ctbody>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>Wrapper<T>\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>queryWrapper\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">实体对象封装操作类（可以为 \u003Ccode>null\u003C\u002Fcode>）\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>IPage<T>\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>page\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">分页查询条件（可以为 \u003Ccode>RowBounds.DEFAULT\u003C\u002Fcode>）\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003C\u002Ftbody>\n\u003C\u002Ftable>\n\u003Ch4>示例代码\u003C\u002Fh4>\n\u003Cp>接下来，本文来演示一些示例代码以便你快速了解如何使用分页查询：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>\u002F\u002F 组装查询条件\nQueryWrapper<User> queryWrapper = new QueryWrapper<>();\n\u002F\u002F where age = 30\nqueryWrapper.eq("age", 30);\n\n\u002F\u002F 查询第 2 页数据，每页 10 条\nPage<User> page = new Page<>(2, 10);\n\npage = userMapper.selectPage(page, queryWrapper);\nSystem.out.println("总记录数：" + page.getTotal());\nSystem.out.println("总共多少页：" + page.getPages());\nSystem.out.println("当前页码：" + page.getCurrent());\n\u002F\u002F 当前页数据\nList<User> users = page.getRecords();\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Cp>执行上面的代码，实际上执行了两条 SQL ： 先执行 \u003Ccode>COUNT(*)\u003C\u002Fcode> 查询出记录总数，然后才是分页语句 \u003Ccode>LIMIT\u003C\u002Fcode>:\u003C\u002Fp>\n\u003Cp>\n\u003Cimg src=\"\u002Fupload\u002F167248872739375-JHcV.jpg\" loading=\"lazy\">\n\u003C\u002Fp>\n\u003Ch5>Page 类说明\u003C\u002Fh5>\n\u003Cblockquote>\n\u003Cp>该类继承了 \u003Ccode>IPage\u003C\u002Fcode> 类，实现了 \u003Cem>简单分页模型\u003C\u002Fem> ，如果你要实现自己的分页模型可以继承 \u003Ccode>Page\u003C\u002Fcode> 类或者实现 \u003Ccode>IPage\u003C\u002Fcode> 类\u003C\u002Fp>\n\u003C\u002Fblockquote>\n\u003Ctable>\n\u003Cthead>\n\u003Ctr>\n\u003Cth align=\"center\">属性名\u003C\u002Fth>\n\u003Cth align=\"center\">类型\u003C\u002Fth>\n\u003Cth align=\"center\">默认值\u003C\u002Fth>\n\u003Cth align=\"center\">描述\u003C\u002Fth>\n\u003C\u002Ftr>\n\u003C\u002Fthead>\n\u003Ctbody>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>records\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>List\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>emptyList\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">查询数据列表\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>total\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>Long\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">0\u003C\u002Ftd>\n\u003Ctd align=\"center\">查询列表总记录数\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>size\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>Long\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">10\u003C\u002Ftd>\n\u003Ctd align=\"center\">每页显示条数，默认 \u003Ccode>10\u003C\u002Fcode>\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>current\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>Long\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">1\u003C\u002Ftd>\n\u003Ctd align=\"center\">当前页\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>orders\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>List\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>emptyList\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">排序字段信息，允许前端传入的时候，注意 SQL 注入问题，可以使用 \u003Ccode>SqlInjectionUtils.check(...)\u003C\u002Fcode> 检查文本\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>optimizeCountSql\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>boolean\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>true\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">自动优化 COUNT SQL 如果遇到 \u003Ccode>jSqlParser\u003C\u002Fcode> 无法解析情况，设置该参数为 \u003Ccode>false\u003C\u002Fcode>\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>optimizeJoinOfCountSql\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>boolean\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>true\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">自动优化 \u003Ccode>COUNT SQL\u003C\u002Fcode> 是否把 \u003Ccode>join\u003C\u002Fcode> 查询部分移除\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>searchCount\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>boolean\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>true\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">是否进行 count 查询，如果指向查询到列表不要查询总记录数，设置该参数为 \u003Ccode>false\u003C\u002Fcode>\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>maxLimit\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>Long\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003C\u002Ftd>\n\u003Ctd align=\"center\">单页分页条数限制\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>countId\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>String\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>xml\u003C\u002Fcode> 自定义 \u003Ccode>count\u003C\u002Fcode> 查询的 \u003Ccode>statementId\u003C\u002Fcode>\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003C\u002Ftbody>\n\u003C\u002Ftable>\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>Service 层封装的分页相关方法如下：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>\u002F\u002F 无条件分页查询\nIPage<T> page(IPage<T> page);\n\u002F\u002F 条件分页查询\nIPage<T> page(IPage<T> page, Wrapper<T> queryWrapper);\n\u002F\u002F 无条件分页查询\nIPage<Map<String, Object>> pageMaps(IPage<T> page);\n\u002F\u002F 条件分页查询\nIPage<Map<String, Object>> pageMaps(IPage<T> page, Wrapper<T> queryWrapper);\n\u003C\u002Fcode>\u003C\u002Fpre>\n\u003Ch4>示例代码\u003C\u002Fh4>\n\u003Cp>Service 层的分页方法入参和 Mapper 差不多：\u003C\u002Fp>\n\u003Cpre>\u003Ccode>\u002F\u002F 组装查询条件\nQueryWrapper<User> queryWrapper = new QueryWrapper<>();\n\u002F\u002F where age = 30\nqueryWrapper.eq("age", 30);\n\n\u002F\u002F 查询第 2 页数据，每页 10 条\nPage<User> page = new Page<>(2, 10);\n\npage = userService.page(page, queryWrapper);\nSystem.out.println("总记录数：" + page.getTotal());\nSystem.out.println("总共多少页：" + page.getPages());\nSystem.out.println("当前页码：" + page.getCurrent());\n\u002F\u002F 当前页数据\nList<User> users = page.getRecords();\n\u003C\u002Fcode>\u003C\u002Fpre>\n15:T9a49,\u003Cp>大家好。\u003C\u002Fp>\n\u003Cp>本小节中，我们将学习如何通过 Mybatis Plus 分页查询数据库表中的数据。\u003C\u002Fp>\n\u003Ch2 id=\"toc-0\">什么是分页查询？\u003C\u002Fh2>\n\u003Cp>下图是从京东上查询关键词 \u003Cem>「手机」\u003C\u002Fem> ，展示的手机数据就是分页查询，共有 91 页：\u003C\u002Fp>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167246380737773-bixm.jpg\" loading=\"lazy\" title=\"京东商城的分页查询\" alt=\"京东商城的分页查询\">\u003C\u002Fdiv>\u003Cspan class=\"image-caption\">京东商城的分页查询\u003C\u002Fspan>\n\u003C\u002Fp>\n\u003Cp>分页查询就是\u003Cstrong>把需要查询的数据集进行分批展示\u003C\u002Fstrong>，比如商品表中有 1万 条手机数据，每页按固定数量展示。\u003C\u002Fp>\n\u003Ch2 id=\"toc-1\">为什么需要分页查询？\u003C\u002Fh2>\n\u003Col>\n\u003Cli>\n\u003Cp>前端页面能够展示的内容有限；\u003C\u002Fp>\n\u003C\u002Fli>\n\u003Cli>\n\u003Cp>当数据库中数据量太多，比如 100W 条，一次性全部返回，查询速度慢，而且内存也顶不住；\u003C\u002Fp>\n\u003C\u002Fli>\n\u003C\u002Fol>\n\u003Ch2 id=\"toc-2\">表结构\u003C\u002Fh2>\n\u003Cp>了解到分页查询相关概念后，我们来上手 Mybatis Plus 的分页查询功能，还是之前小节中定义好的用户测试表， 执行脚本如下：\u003C\u002Fp>\n\u003Cdiv class=\"language-sql\" data-ext=\"sql\" data-code=\"DROP%20TABLE%20IF%20EXISTS%20user%3B%0A%0ACREATE%20TABLE%20%60user%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> \u003Cspan class=\"token keyword\">user\u003C\u002Fspan>\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>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-3\">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=\"%40TableName(%22user%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\">@TableName\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token string\">\"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>不明白 Mybatis Plus 实体类注解的小伙伴，可参考前面小节\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>, 有详细解释。\u003C\u002Fp>\n\u003Ch2 id=\"toc-4\">新增测试数据\u003C\u002Fh2>\n\u003Cp>分页查询前，先通过代码插入一些测试数据，执行代码如下：\u003C\u002Fp>\n\u003Cdiv class=\"language-dockerfile\" data-ext=\"dockerfile\" data-code=\"%2F%2F%20%E5%BE%AA%E7%8E%AF%E6%8F%92%E5%85%A5%20100%20%E6%9D%A1%E6%B5%8B%E8%AF%95%E6%95%B0%E6%8D%AE%0Afor%20(int%20i%20%3D%200%3B%20i%20%3C%20100%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%0A%20%20%20%20userMapper.insert(user)%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-dockerfile\">\u002F\u002F 循环插入 100 条测试数据\nfor (int i = 0; i < 100; 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\n    userMapper.insert(user);\n}\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cblockquote>\n\u003Cp>TIP : 不清楚如何插入数据可翻阅前面 《新增数据》\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> 小节；\u003C\u002Fp>\n\u003C\u002Fblockquote>\n\u003Ch2 id=\"toc-5\">添加分页插件\u003C\u002Fh2>\n\u003Cp>接着，在 \u003Ccode>MybatisPlusConfig\u003C\u002Fcode> 配置类中，添加分页插件 \u003Ccode>PaginationInnerInterceptor\u003C\u002Fcode>:\u003C\u002Fp>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167247912020155-YPWW.jpg\" loading=\"lazy\">\u003C\u002Fdiv>\n\u003C\u002Fp>\n\u003Cdiv class=\"language-java\" data-ext=\"java\" data-code=\"%2F**%0A%20*%20%40Author%3A%20%E5%BC%A0%E4%B8%89%0A%20*%20%40From%3A%20%E5%85%AC%E4%BC%97%E5%8F%B7%EF%BC%9A%E5%BC%A0%E4%B8%89%2C%20%E7%BD%91%E7%AB%99%EF%BC%9Awww.mashangan.com%0A%20*%20%40Date%3A%202022-12-15%2018%3A29%0A%20*%20%40Version%3A%20v1.0.0%0A%20*%20%40Description%3A%20TODO%0A%20**%2F%0A%40Configuration%0A%40MapperScan(%22com.mashangan.mybatisplusdemo.mapper%22)%0Apublic%20class%20MybatisPlusConfig%20%7B%0A%0A%20%20%20%20%2F**%0A%20%20%20%20%20*%20%E5%88%86%E9%A1%B5%E6%8F%92%E4%BB%B6%0A%20%20%20%20%20*%20%40return%0A%20%20%20%20%20*%2F%0A%20%20%20%20%40Bean%0A%20%20%20%20public%20MybatisPlusInterceptor%20mybatisPlusInterceptor()%7B%0A%20%20%20%20%20%20%20%20MybatisPlusInterceptor%20interceptor%20%3D%20new%20MybatisPlusInterceptor()%3B%0A%20%20%20%20%20%20%20%20interceptor.addInnerInterceptor(new%20PaginationInnerInterceptor())%3B%0A%20%20%20%20%20%20%20%20return%20interceptor%3B%0A%20%20%20%20%7D%0A%20%20%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 comment\">\u002F**\n * @Author: 张三\n * @Date: 2022-12-15 18:29\n * @Version: v1.0.0\n * @Description: TODO\n **\u002F\u003C\u002Fspan>\n\u003Cspan class=\"token annotation punctuation\">@Configuration\u003C\u002Fspan>\n\u003Cspan class=\"token annotation punctuation\">@MapperScan\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token string\">\"com.mashangan.mybatisplusdemo.mapper\"\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\">MybatisPlusConfig\u003C\u002Fspan> \u003Cspan class=\"token punctuation\">{\u003C\u002Fspan>\n\n    \u003Cspan class=\"token comment\">\u002F**\n     * 分页插件\n     * @return\n     *\u002F\u003C\u002Fspan>\n    \u003Cspan class=\"token annotation punctuation\">@Bean\u003C\u002Fspan>\n    \u003Cspan class=\"token keyword\">public\u003C\u002Fspan> \u003Cspan class=\"token class-name\">MybatisPlusInterceptor\u003C\u002Fspan> \u003Cspan class=\"token function\">mybatisPlusInterceptor\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">{\u003C\u002Fspan>\n        \u003Cspan class=\"token class-name\">MybatisPlusInterceptor\u003C\u002Fspan> interceptor \u003Cspan class=\"token operator\">=\u003C\u002Fspan> \u003Cspan class=\"token keyword\">new\u003C\u002Fspan> \u003Cspan class=\"token class-name\">MybatisPlusInterceptor\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n        interceptor\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">addInnerInterceptor\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token keyword\">new\u003C\u002Fspan> \u003Cspan class=\"token class-name\">PaginationInnerInterceptor\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\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\">return\u003C\u002Fspan> interceptor\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n    \u003Cspan class=\"token punctuation\">}\u003C\u002Fspan>\n  \n\u003Cspan class=\"token punctuation\">}\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Ch2 id=\"toc-6\">开始分页查询数据\u003C\u002Fh2>\n\u003Cp>Mybatis Plus 对 Mapper 层和 Service 层都将常见的增删改查操作封装好了，只需简单的继承，即可轻松搞定对数据的增删改查，本文重点讲解分页查询相关的部分。\u003C\u002Fp>\n\u003Ch3 id=\"toc-7\">Mapper 层\u003C\u002Fh3>\n\u003Cp>定义一个 \u003Ccode>UserMapper\u003C\u002Fcode> , 让其继承自 \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> 提供的分页查询相关的方法如下：\u003C\u002Fp>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167246462284126-HAVn.jpg\" loading=\"lazy\">\u003C\u002Fdiv>\n\u003C\u002Fp>\n\u003Cp>解释一下每个方法的作用：\u003C\u002Fp>\n\u003Cdiv class=\"language-xml\" data-ext=\"xml\" data-code=\"%2F%2F%20%E5%88%86%E9%A1%B5%E6%9F%A5%E8%AF%A2%EF%BC%8Cpage%20%E7%94%A8%E4%BA%8E%E8%AE%BE%E7%BD%AE%E9%9C%80%E8%A6%81%E6%9F%A5%E8%AF%A2%E7%9A%84%E9%A1%B5%E6%95%B0%EF%BC%8C%E4%BB%A5%E5%8F%8A%E6%AF%8F%E9%A1%B5%E5%B1%95%E7%A4%BA%E6%95%B0%E6%8D%AE%E9%87%8F%EF%BC%8Cwrapper%20%E7%94%A8%E4%BA%8E%E7%BB%84%E8%A3%85%E6%9F%A5%E8%AF%A2%E6%9D%A1%E4%BB%B6%0AIPage%3CT%3E%20selectPage(IPage%3CT%3E%20page%2C%20Wrapper%3CT%3E%20queryWrapper)%3B%0A%2F%2F%20%E5%90%8C%E4%B8%8A%EF%BC%8C%E5%8C%BA%E5%88%AB%E6%98%AF%E7%94%A8%20map%20%E6%9D%A5%E6%8E%A5%E5%8F%97%E6%9F%A5%E8%AF%A2%E7%9A%84%E6%95%B0%E6%8D%AE%0AIPage%3CMap%3CString%2C%20Object%3E%3E%20selectMapsPage(IPage%3CT%3E%20page%2C%20Wrapper%3CT%3E%20queryWrapper)%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-xml\">\u002F\u002F 分页查询，page 用于设置需要查询的页数，以及每页展示数据量，wrapper 用于组装查询条件\nIPage\u003Cspan class=\"token tag\">\u003Cspan class=\"token tag\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>T\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> selectPage(IPage\u003Cspan class=\"token tag\">\u003Cspan class=\"token tag\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>T\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> page, Wrapper\u003Cspan class=\"token tag\">\u003Cspan class=\"token tag\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>T\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> queryWrapper);\n\u002F\u002F 同上，区别是用 map 来接受查询的数据\nIPage<Map\u003Cspan class=\"token tag\">\u003Cspan class=\"token tag\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>String,\u003C\u002Fspan> \u003Cspan class=\"token attr-name\">Object\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan>> selectMapsPage(IPage\u003Cspan class=\"token tag\">\u003Cspan class=\"token tag\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>T\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> page, Wrapper\u003Cspan class=\"token tag\">\u003Cspan class=\"token tag\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>T\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan> queryWrapper);\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>参数说明：\u003C\u002Fp>\n\u003Ctable>\n\u003Cthead>\n\u003Ctr>\n\u003Cth align=\"center\">类型\u003C\u002Fth>\n\u003Cth align=\"center\">参数名\u003C\u002Fth>\n\u003Cth align=\"center\">描述\u003C\u002Fth>\n\u003C\u002Ftr>\n\u003C\u002Fthead>\n\u003Ctbody>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>Wrapper<T>\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>queryWrapper\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">实体对象封装操作类（可以为 \u003Ccode>null\u003C\u002Fcode>）\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>IPage<T>\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>page\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">分页查询条件（可以为 \u003Ccode>RowBounds.DEFAULT\u003C\u002Fcode>）\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003C\u002Ftbody>\n\u003C\u002Ftable>\n\u003Ch4 id=\"toc-8\">示例代码\u003C\u002Fh4>\n\u003Cp>接下来，本文来演示一些示例代码以便你快速了解如何使用分页查询：\u003C\u002Fp>\n\u003Cdiv class=\"language-java\" data-ext=\"java\" data-code=\"%2F%2F%20%E7%BB%84%E8%A3%85%E6%9F%A5%E8%AF%A2%E6%9D%A1%E4%BB%B6%0AQueryWrapper%3CUser%3E%20queryWrapper%20%3D%20new%20QueryWrapper%3C%3E()%3B%0A%2F%2F%20where%20age%20%3D%2030%0AqueryWrapper.eq(%22age%22%2C%2030)%3B%0A%0A%2F%2F%20%E6%9F%A5%E8%AF%A2%E7%AC%AC%202%20%E9%A1%B5%E6%95%B0%E6%8D%AE%EF%BC%8C%E6%AF%8F%E9%A1%B5%2010%20%E6%9D%A1%0APage%3CUser%3E%20page%20%3D%20new%20Page%3C%3E(2%2C%2010)%3B%0A%0Apage%20%3D%20userMapper.selectPage(page%2C%20queryWrapper)%3B%0ASystem.out.println(%22%E6%80%BB%E8%AE%B0%E5%BD%95%E6%95%B0%EF%BC%9A%22%20%2B%20page.getTotal())%3B%0ASystem.out.println(%22%E6%80%BB%E5%85%B1%E5%A4%9A%E5%B0%91%E9%A1%B5%EF%BC%9A%22%20%2B%20page.getPages())%3B%0ASystem.out.println(%22%E5%BD%93%E5%89%8D%E9%A1%B5%E7%A0%81%EF%BC%9A%22%20%2B%20page.getCurrent())%3B%0A%2F%2F%20%E5%BD%93%E5%89%8D%E9%A1%B5%E6%95%B0%E6%8D%AE%0AList%3CUser%3E%20users%20%3D%20page.getRecords()%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 comment\">\u002F\u002F 组装查询条件\u003C\u002Fspan>\n\u003Cspan class=\"token class-name\">QueryWrapper\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> queryWrapper \u003Cspan class=\"token operator\">=\u003C\u002Fspan> \u003Cspan class=\"token keyword\">new\u003C\u002Fspan> \u003Cspan class=\"token class-name\">QueryWrapper\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\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 where age = 30\u003C\u002Fspan>\nqueryWrapper\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">eq\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token string\">\"age\"\u003C\u002Fspan>\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\n\u003Cspan class=\"token comment\">\u002F\u002F 查询第 2 页数据，每页 10 条\u003C\u002Fspan>\n\u003Cspan class=\"token class-name\">Page\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> page \u003Cspan class=\"token operator\">=\u003C\u002Fspan> \u003Cspan class=\"token keyword\">new\u003C\u002Fspan> \u003Cspan class=\"token class-name\">Page\u003C\u002Fspan>\u003Cspan class=\"token generics\">\u003Cspan class=\"token punctuation\"><\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">>\u003C\u002Fspan>\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token number\">2\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> \u003Cspan class=\"token number\">10\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\npage \u003Cspan class=\"token operator\">=\u003C\u002Fspan> userMapper\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">selectPage\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>page\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> queryWrapper\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token class-name\">System\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>out\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">println\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token string\">\"总记录数：\"\u003C\u002Fspan> \u003Cspan class=\"token operator\">+\u003C\u002Fspan> page\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">getTotal\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token class-name\">System\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>out\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">println\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token string\">\"总共多少页：\"\u003C\u002Fspan> \u003Cspan class=\"token operator\">+\u003C\u002Fspan> page\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">getPages\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token class-name\">System\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>out\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">println\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token string\">\"当前页码：\"\u003C\u002Fspan> \u003Cspan class=\"token operator\">+\u003C\u002Fspan> page\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">getCurrent\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\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 当前页数据\u003C\u002Fspan>\n\u003Cspan class=\"token class-name\">List\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> users \u003Cspan class=\"token operator\">=\u003C\u002Fspan> page\u003Cspan class=\"token punctuation\">.\u003C\u002Fspan>\u003Cspan class=\"token function\">getRecords\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Cp>执行上面的代码，实际上执行了两条 SQL ： 先执行 \u003Ccode>COUNT(*)\u003C\u002Fcode> 查询出记录总数，然后才是分页语句 \u003Ccode>LIMIT\u003C\u002Fcode>:\u003C\u002Fp>\n\u003Cp>\n\u003Cdiv class=\"img-loading\">\u003Cimg src=\"\u002Fupload\u002F167248872739375-JHcV.jpg\" loading=\"lazy\">\u003C\u002Fdiv>\n\u003C\u002Fp>\n\u003Ch5 id=\"toc-9\">Page 类说明\u003C\u002Fh5>\n\u003Cblockquote>\n\u003Cp>该类继承了 \u003Ccode>IPage\u003C\u002Fcode> 类，实现了 \u003Cem>简单分页模型\u003C\u002Fem> ，如果你要实现自己的分页模型可以继承 \u003Ccode>Page\u003C\u002Fcode> 类或者实现 \u003Ccode>IPage\u003C\u002Fcode> 类\u003C\u002Fp>\n\u003C\u002Fblockquote>\n\u003Ctable>\n\u003Cthead>\n\u003Ctr>\n\u003Cth align=\"center\">属性名\u003C\u002Fth>\n\u003Cth align=\"center\">类型\u003C\u002Fth>\n\u003Cth align=\"center\">默认值\u003C\u002Fth>\n\u003Cth align=\"center\">描述\u003C\u002Fth>\n\u003C\u002Ftr>\n\u003C\u002Fthead>\n\u003Ctbody>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>records\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>List\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>emptyList\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">查询数据列表\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>total\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>Long\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">0\u003C\u002Ftd>\n\u003Ctd align=\"center\">查询列表总记录数\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>size\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>Long\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">10\u003C\u002Ftd>\n\u003Ctd align=\"center\">每页显示条数，默认 \u003Ccode>10\u003C\u002Fcode>\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>current\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>Long\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">1\u003C\u002Ftd>\n\u003Ctd align=\"center\">当前页\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>orders\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>List\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>emptyList\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">排序字段信息，允许前端传入的时候，注意 SQL 注入问题，可以使用 \u003Ccode>SqlInjectionUtils.check(...)\u003C\u002Fcode> 检查文本\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>optimizeCountSql\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>boolean\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>true\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">自动优化 COUNT SQL 如果遇到 \u003Ccode>jSqlParser\u003C\u002Fcode> 无法解析情况，设置该参数为 \u003Ccode>false\u003C\u002Fcode>\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>optimizeJoinOfCountSql\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>boolean\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>true\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">自动优化 \u003Ccode>COUNT SQL\u003C\u002Fcode> 是否把 \u003Ccode>join\u003C\u002Fcode> 查询部分移除\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>searchCount\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>boolean\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>true\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">是否进行 count 查询，如果指向查询到列表不要查询总记录数，设置该参数为 \u003Ccode>false\u003C\u002Fcode>\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>maxLimit\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>Long\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003C\u002Ftd>\n\u003Ctd align=\"center\">单页分页条数限制\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003Ctr>\n\u003Ctd align=\"center\">\u003Ccode>countId\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>String\u003C\u002Fcode>\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003C\u002Ftd>\n\u003Ctd align=\"center\">\u003Ccode>xml\u003C\u002Fcode> 自定义 \u003Ccode>count\u003C\u002Fcode> 查询的 \u003Ccode>statementId\u003C\u002Fcode>\u003C\u002Ftd>\n\u003C\u002Ftr>\n\u003C\u002Ftbody>\n\u003C\u002Ftable>\n\u003Ch3 id=\"toc-10\">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>Service 层封装的分页相关方法如下：\u003C\u002Fp>\n\u003Cdiv class=\"language-javascript\" data-ext=\"javascript\" data-code=\"%2F%2F%20%E6%97%A0%E6%9D%A1%E4%BB%B6%E5%88%86%E9%A1%B5%E6%9F%A5%E8%AF%A2%0AIPage%3CT%3E%20page(IPage%3CT%3E%20page)%3B%0A%2F%2F%20%E6%9D%A1%E4%BB%B6%E5%88%86%E9%A1%B5%E6%9F%A5%E8%AF%A2%0AIPage%3CT%3E%20page(IPage%3CT%3E%20page%2C%20Wrapper%3CT%3E%20queryWrapper)%3B%0A%2F%2F%20%E6%97%A0%E6%9D%A1%E4%BB%B6%E5%88%86%E9%A1%B5%E6%9F%A5%E8%AF%A2%0AIPage%3CMap%3CString%2C%20Object%3E%3E%20pageMaps(IPage%3CT%3E%20page)%3B%0A%2F%2F%20%E6%9D%A1%E4%BB%B6%E5%88%86%E9%A1%B5%E6%9F%A5%E8%AF%A2%0AIPage%3CMap%3CString%2C%20Object%3E%3E%20pageMaps(IPage%3CT%3E%20page%2C%20Wrapper%3CT%3E%20queryWrapper)%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-javascript\">\u003Cspan class=\"token comment\">\u002F\u002F 无条件分页查询\u003C\u002Fspan>\nIPage\u003Cspan class=\"token operator\"><\u003C\u002Fspan>\u003Cspan class=\"token constant\">T\u003C\u002Fspan>\u003Cspan class=\"token operator\">>\u003C\u002Fspan> \u003Cspan class=\"token function\">page\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>IPage\u003Cspan class=\"token operator\"><\u003C\u002Fspan>\u003Cspan class=\"token constant\">T\u003C\u002Fspan>\u003Cspan class=\"token operator\">>\u003C\u002Fspan> page\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token comment\">\u002F\u002F 条件分页查询\u003C\u002Fspan>\nIPage\u003Cspan class=\"token operator\"><\u003C\u002Fspan>\u003Cspan class=\"token constant\">T\u003C\u002Fspan>\u003Cspan class=\"token operator\">>\u003C\u002Fspan> \u003Cspan class=\"token function\">page\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>IPage\u003Cspan class=\"token operator\"><\u003C\u002Fspan>\u003Cspan class=\"token constant\">T\u003C\u002Fspan>\u003Cspan class=\"token operator\">>\u003C\u002Fspan> page\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> Wrapper\u003Cspan class=\"token operator\"><\u003C\u002Fspan>\u003Cspan class=\"token constant\">T\u003C\u002Fspan>\u003Cspan class=\"token operator\">>\u003C\u002Fspan> queryWrapper\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token comment\">\u002F\u002F 无条件分页查询\u003C\u002Fspan>\nIPage\u003Cspan class=\"token operator\"><\u003C\u002Fspan>Map\u003Cspan class=\"token operator\"><\u003C\u002Fspan>String\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> Object\u003Cspan class=\"token operator\">>>\u003C\u002Fspan> \u003Cspan class=\"token function\">pageMaps\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>IPage\u003Cspan class=\"token operator\"><\u003C\u002Fspan>\u003Cspan class=\"token constant\">T\u003C\u002Fspan>\u003Cspan class=\"token operator\">>\u003C\u002Fspan> page\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003Cspan class=\"token comment\">\u002F\u002F 条件分页查询\u003C\u002Fspan>\nIPage\u003Cspan class=\"token operator\"><\u003C\u002Fspan>Map\u003Cspan class=\"token operator\"><\u003C\u002Fspan>String\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> Object\u003Cspan class=\"token operator\">>>\u003C\u002Fspan> \u003Cspan class=\"token function\">pageMaps\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">(\u003C\u002Fspan>IPage\u003Cspan class=\"token operator\"><\u003C\u002Fspan>\u003Cspan class=\"token constant\">T\u003C\u002Fspan>\u003Cspan class=\"token operator\">>\u003C\u002Fspan> page\u003Cspan class=\"token punctuation\">,\u003C\u002Fspan> Wrapper\u003Cspan class=\"token operator\"><\u003C\u002Fspan>\u003Cspan class=\"token constant\">T\u003C\u002Fspan>\u003Cspan class=\"token operator\">>\u003C\u002Fspan> queryWrapper\u003Cspan class=\"token punctuation\">)\u003C\u002Fspan>\u003Cspan class=\"token punctuation\">;\u003C\u002Fspan>\n\u003C\u002Fcode>\u003C\u002Fpre>\n      \u003C\u002Fdiv>\n\u003Ch4 id=\"toc-11\">示例代码\u003C\u002Fh4>\n\u003Cp>Service 层的分页方法入参和 Mapper 差不多：\u003C\u002Fp>"]