{"id":5816,"date":"2024-04-16T00:11:17","date_gmt":"2024-04-15T16:11:17","guid":{"rendered":"http:\/\/zyg.luchers.cn\/?p=5816"},"modified":"2024-04-16T00:11:17","modified_gmt":"2024-04-15T16:11:17","slug":"%e4%ba%8c%e3%80%81mybatis-plus%e6%a0%b8%e5%bf%83%e5%8a%9f%e8%83%bd%ef%bc%88%e5%9f%ba%e4%ba%8emapper-service%e6%8e%a5%e5%8f%a3%e7%9a%84crud%e3%80%81%e5%88%86%e9%a1%b5%e6%9f%a5%e8%af%a2%e3%80%81","status":"publish","type":"post","link":"http:\/\/zyg.luchers.cn\/index.php\/2024\/04\/16\/%e4%ba%8c%e3%80%81mybatis-plus%e6%a0%b8%e5%bf%83%e5%8a%9f%e8%83%bd%ef%bc%88%e5%9f%ba%e4%ba%8emapper-service%e6%8e%a5%e5%8f%a3%e7%9a%84crud%e3%80%81%e5%88%86%e9%a1%b5%e6%9f%a5%e8%af%a2%e3%80%81\/","title":{"rendered":"\u4e8c\u3001Mybatis-Plus\u6838\u5fc3\u529f\u80fd\uff08\u57fa\u4e8eMapper\/Service\u63a5\u53e3\u7684CRUD\u3001\u5206\u9875\u67e5\u8be2\u3001\u6761\u4ef6\u6784\u9020\u5668\u3001\u6838\u5fc3\u6ce8\u89e3\u4f7f\u7528\uff09"},"content":{"rendered":"<h1>\u4e8c\u3001Mybatis-Plus\u6838\u5fc3\u529f\u80fd<\/h1>\n<h2>1\u3001\u57fa\u4e8eMapper\u63a5\u53e3\u7684CRUD<\/h2>\n<p>1\u3001\u901a\u7528 CRUD \u5c01\u88c5BaseMapper (opens new window)\u63a5\u53e3\uff0c Mybatis-Plus \u542f\u52a8\u65f6\u81ea\u52a8\u89e3\u6790\u5b9e\u4f53\u8868\u5173\u7cfb\u6620\u5c04\u8f6c\u6362\u4e3a Mybatis \u5185\u90e8\u5bf9\u8c61\u6ce8\u5165\u5bb9\u5668! \u5185\u90e8\u5305\u542b\u5e38\u89c1\u7684\u5355\u8868\u64cd\u4f5c\uff01<\/p>\n<h3>1\u3001Insert\u65b9\u6cd5<\/h3>\n<h4>1\u3001\u683c\u5f0f<\/h4>\n<pre><code class=\"language-java\">\/\/ \u63d2\u5165\u4e00\u6761\u8bb0\u5f55\n\/\/ T \u5c31\u662f\u8981\u63d2\u5165\u7684\u5b9e\u4f53\u5bf9\u8c61\n\/\/ \u9ed8\u8ba4\u4e3b\u952e\u751f\u6210\u7b56\u7565\u4e3a\u96ea\u82b1\u7b97\u6cd5\uff08\u540e\u9762\u8bb2\u89e3\uff09\nint insert(T entity);<\/code><\/pre>\n<h4>2\u3001\u63cf\u8ff0<\/h4>\n<table>\n<thead>\n<tr>\n<th>\u7c7b\u578b<\/th>\n<th>\u53c2\u6570\u540d<\/th>\n<th>\u63cf\u8ff0<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>T<\/td>\n<td>entity<\/td>\n<td>\u5b9e\u4f53\u5bf9\u8c61<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>2\u3001Delete\u65b9\u6cd5<\/h3>\n<h4>1\u3001\u683c\u5f0f<\/h4>\n<pre><code class=\"language-java\">\/\/ \u6839\u636e entity \u6761\u4ef6\uff0c\u5220\u9664\u8bb0\u5f55\nint delete(@Param(Constants.WRAPPER) Wrapper&lt;T&gt; wrapper);\n\n\/\/ \u5220\u9664\uff08\u6839\u636eID \u6279\u91cf\u5220\u9664\uff09\nint deleteBatchIds(@Param(Constants.COLLECTION) Collection&lt;? extends Serializable&gt; idList);\n\n\/\/ \u6839\u636e ID \u5220\u9664\nint deleteById(Serializable id);\n\n\/\/ \u6839\u636e columnMap \u6761\u4ef6\uff0c\u5220\u9664\u8bb0\u5f55\nint deleteByMap(@Param(Constants.COLUMN_MAP) Map&lt;String, Object&gt; columnMap);<\/code><\/pre>\n<h4>2\u3001\u63cf\u8ff0<\/h4>\n<table>\n<thead>\n<tr>\n<th>\u7c7b\u578b<\/th>\n<th>\u53c2\u6570\u540d<\/th>\n<th>\u63cf\u8ff0<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Wrapper<T><\/td>\n<td>wrapper<\/td>\n<td>\u5b9e\u4f53\u5bf9\u8c61\u5c01\u88c5\u64cd\u4f5c\u7c7b\uff08\u53ef\u4ee5\u4e3a null\uff09<\/td>\n<\/tr>\n<tr>\n<td>Collection&lt;? extends Serializable&gt;<\/td>\n<td>idList<\/td>\n<td>\u4e3b\u952e ID \u5217\u8868(\u4e0d\u80fd\u4e3a null \u4ee5\u53ca empty)<\/td>\n<\/tr>\n<tr>\n<td>Serializable<\/td>\n<td>id<\/td>\n<td>\u4e3b\u952e ID<\/td>\n<\/tr>\n<tr>\n<td>Map&lt;String, Object&gt;<\/td>\n<td>columnMap<\/td>\n<td>\u8868\u5b57\u6bb5 map \u5bf9\u8c61<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>3\u3001Update\u65b9\u6cd5<\/h3>\n<h4>1\u3001\u683c\u5f0f<\/h4>\n<pre><code class=\"language-java\">\/\/ \u6839\u636e whereWrapper \u6761\u4ef6\uff0c\u66f4\u65b0\u8bb0\u5f55\nint update(@Param(Constants.ENTITY) T updateEntity, \n            @Param(Constants.WRAPPER) Wrapper&lt;T&gt; whereWrapper);\n\n\/\/ \u6839\u636e ID \u4fee\u6539  \u4e3b\u952e\u5c5e\u6027\u5fc5\u987b\u503c\nint updateById(@Param(Constants.ENTITY) T entity);<\/code><\/pre>\n<h4>2\u3001\u63cf\u8ff0<\/h4>\n<table>\n<thead>\n<tr>\n<th>\u7c7b\u578b<\/th>\n<th>\u53c2\u6570\u540d<\/th>\n<th>\u63cf\u8ff0<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>T<\/td>\n<td>entity<\/td>\n<td>\u5b9e\u4f53\u5bf9\u8c61 (set \u6761\u4ef6\u503c,\u53ef\u4e3a null)<\/td>\n<\/tr>\n<tr>\n<td>Wrapper<T><\/td>\n<td>updateWrapper<\/td>\n<td>\u5b9e\u4f53\u5bf9\u8c61\u5c01\u88c5\u64cd\u4f5c\u7c7b\uff08\u53ef\u4ee5\u4e3a null,\u91cc\u9762\u7684 entity \u7528\u4e8e\u751f\u6210 where \u8bed\u53e5\uff09<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>4\u3001Select\u65b9\u6cd5<\/h3>\n<h4>1\u3001\u683c\u5f0f<\/h4>\n<pre><code class=\"language-java\">\/\/ \u6839\u636e ID \u67e5\u8be2\nT selectById(Serializable id);\n\n\/\/ \u6839\u636e entity \u6761\u4ef6\uff0c\u67e5\u8be2\u4e00\u6761\u8bb0\u5f55\nT selectOne(@Param(Constants.WRAPPER) Wrapper&lt;T&gt; queryWrapper);\n\n\/\/ \u67e5\u8be2\uff08\u6839\u636eID \u6279\u91cf\u67e5\u8be2\uff09\nList&lt;T&gt; selectBatchIds(@Param(Constants.COLLECTION) Collection&lt;? extends Serializable&gt; idList);\n\n\/\/ \u6839\u636e entity \u6761\u4ef6\uff0c\u67e5\u8be2\u5168\u90e8\u8bb0\u5f55\nList&lt;T&gt; selectList(@Param(Constants.WRAPPER) Wrapper&lt;T&gt; queryWrapper);\n\n\/\/ \u67e5\u8be2\uff08\u6839\u636e columnMap \u6761\u4ef6\uff09\nList&lt;T&gt; selectByMap(@Param(Constants.COLUMN_MAP) Map&lt;String, Object&gt; columnMap);\n\n\/\/ \u6839\u636e Wrapper \u6761\u4ef6\uff0c\u67e5\u8be2\u5168\u90e8\u8bb0\u5f55\nList&lt;Map&lt;String, Object&gt;&gt; selectMaps(@Param(Constants.WRAPPER) Wrapper&lt;T&gt; queryWrapper);\n\n\/\/ \u6839\u636e Wrapper \u6761\u4ef6\uff0c\u67e5\u8be2\u5168\u90e8\u8bb0\u5f55\u3002\u6ce8\u610f\uff1a \u53ea\u8fd4\u56de\u7b2c\u4e00\u4e2a\u5b57\u6bb5\u7684\u503c\nList&lt;Object&gt; selectObjs(@Param(Constants.WRAPPER) Wrapper&lt;T&gt; queryWrapper);\n\n\/\/ \u6839\u636e entity \u6761\u4ef6\uff0c\u67e5\u8be2\u5168\u90e8\u8bb0\u5f55\uff08\u5e76\u7ffb\u9875\uff09\nIPage&lt;T&gt; selectPage(IPage&lt;T&gt; page, @Param(Constants.WRAPPER) Wrapper&lt;T&gt; queryWrapper);\n\n\/\/ \u6839\u636e Wrapper \u6761\u4ef6\uff0c\u67e5\u8be2\u5168\u90e8\u8bb0\u5f55\uff08\u5e76\u7ffb\u9875\uff09\nIPage&lt;Map&lt;String, Object&gt;&gt; selectMapsPage(IPage&lt;T&gt; page, @Param(Constants.WRAPPER) Wrapper&lt;T&gt; queryWrapper);\n\n\/\/ \u6839\u636e Wrapper \u6761\u4ef6\uff0c\u67e5\u8be2\u603b\u8bb0\u5f55\u6570\nInteger selectCount(@Param(Constants.WRAPPER) Wrapper&lt;T&gt; queryWrapper);<\/code><\/pre>\n<h4>2\u3001\u63cf\u8ff0<\/h4>\n<table>\n<thead>\n<tr>\n<th>\u7c7b\u578b<\/th>\n<th>\u53c2\u6570\u540d<\/th>\n<th>\u63cf\u8ff0<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Serializable<\/td>\n<td>id<\/td>\n<td>\u4e3b\u952e ID<\/td>\n<\/tr>\n<tr>\n<td>Wrapper<T><\/td>\n<td>queryWrapper<\/td>\n<td>\u5b9e\u4f53\u5bf9\u8c61\u5c01\u88c5\u64cd\u4f5c\u7c7b\uff08\u53ef\u4ee5\u4e3a null\uff09<\/td>\n<\/tr>\n<tr>\n<td>Collection&lt;? extends Serializable&gt;<\/td>\n<td>idList<\/td>\n<td>\u4e3b\u952e ID \u5217\u8868(\u4e0d\u80fd\u4e3a null \u4ee5\u53ca empty)<\/td>\n<\/tr>\n<tr>\n<td>Map&lt;String, Object&gt;<\/td>\n<td>columnMap<\/td>\n<td>\u8868\u5b57\u6bb5 map \u5bf9\u8c61<\/td>\n<\/tr>\n<tr>\n<td>IPage<T><\/td>\n<td>page<\/td>\n<td>\u5206\u9875\u67e5\u8be2\u6761\u4ef6\uff08\u53ef\u4ee5\u4e3a RowBounds.DEFAULT\uff09<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>5\u3001\u81ea\u5b9a\u4e49\u548c\u591a\u8868\u6620\u5c04<\/h3>\n<h4>1\u3001Mybatis-plus\u9ed8\u8ba4\u7684mapper.xml\u4f4d\u7f6e<\/h4>\n<p>1\u3001\u9ed8\u8ba4\u7684\u4f4d\u7f6e\u5c31\u662f:\/mapper\/*.xml<\/p>\n<p>2\u3001\u6e90\u7801<\/p>\n<pre><code class=\"language-yaml\">mybatis-plus: # mybatis-plus\u7684\u914d\u7f6e\n  # \u9ed8\u8ba4\u4f4d\u7f6e private String[] mapperLocations = new String[]{&quot;classpath*:\/mapper\/**\/*.xml&quot;};    \n  mapper-locations: classpath:\/mapper\/*.xml<\/code><\/pre>\n<h4>2\u3001\u81ea\u5b9a\u4e49\u7684mapper\u65b9\u6cd5<\/h4>\n<p>1\u3001\u5c31\u662f\u5728mapper\u63a5\u53e3\u7c7b\u4e2d\u81ea\u5b9a\u4e49sql\u67e5\u8be2\u7684\u65b9\u6cd5\uff0c\u7136\u540e\u7528mapper.xml\u81ea\u5df1\u53bb\u5199<\/p>\n<p>2\u3001\u4f8b\u5b50\u3010\u81ea\u5b9a\u4e49mapper\u65b9\u6cd5\u3011<\/p>\n<pre><code class=\"language-java\">public interface UserMapper extends BaseMapper&lt;User&gt; {\n\n    \/\/\u6b63\u5e38\u81ea\u5b9a\u4e49\u65b9\u6cd5\uff01\n    \/\/\u53ef\u4ee5\u4f7f\u7528\u6ce8\u89e3@Select\u6216\u8005mapper.xml\u5b9e\u73b0\n    List&lt;User&gt; queryAll();\n}\n<\/code><\/pre>\n<p>3\u3001mapper.xml\u5b9e\u73b0<\/p>\n<pre><code class=\"language-xml\">&lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot; ?&gt;\n&lt;!DOCTYPE mapper\n        PUBLIC &quot;-\/\/mybatis.org\/\/DTD Mapper 3.0\/\/EN&quot;\n        &quot;https:\/\/mybatis.org\/dtd\/mybatis-3-mapper.dtd&quot;&gt;\n&lt;!-- namespace = \u63a5\u53e3\u7684\u5168\u9650\u5b9a\u7b26 --&gt;\n&lt;mapper namespace=&quot;com.atguigu.mapper.UserMapper&quot;&gt;\n\n   &lt;select id=&quot;queryAll&quot; resultType=&quot;user&quot; &gt;\n       select * from user\n   &lt;\/select&gt;\n&lt;\/mapper&gt;<\/code><\/pre>\n<h3>6\u3001\u4f8b\u5b50<\/h3>\n<p>1\u3001\u51c6\u5907\u5de5\u4f5c\u548c\u4e0a\u9762\u7684\u90a3\u4e2a\u5feb\u901f\u5165\u95e8\u4e00\u6837<\/p>\n<h4>1\u3001\u6b65\u9aa4<\/h4>\n<p>1\u3001\u521b\u5efa\u9879\u76ee<\/p>\n<p>2\u3001\u5bfc\u5165\u4f9d\u8d56<\/p>\n<p>3\u3001\u7f16\u5199\u5b9e\u4f53\u7c7b<\/p>\n<p>4\u3001\u7f16\u5199mapper\u63a5\u53e3<\/p>\n<p>5\u3001\u7f16\u5199\u542f\u52a8\u7c7b<\/p>\n<p>6\u3001\u7f16\u5199yaml\u914d\u7f6e\u6587\u4ef6<\/p>\n<p>7\u3001\u7f16\u5199\u6d4b\u8bd5\u65b9\u6cd5<\/p>\n<h4>2\u3001\u5b9e\u73b0<\/h4>\n<p>1\u3001\u5bfc\u5165\u4f9d\u8d56<\/p>\n<ul>\n<li>\u8fd9\u4e2a\u548c\u4e0a\u9762\u90a3\u4e2a\u5feb\u901f\u5165\u95e8\u4f9d\u8d56\u610f\u4e49<\/li>\n<\/ul>\n<p>2\u3001\u7f16\u5199\u5b9e\u4f53\u7c7b<\/p>\n<pre><code class=\"language-java\">package com.atguigu.pojo;\n\nimport lombok.Data;\n\n@Data\npublic class User {\n    private Integer id;\n    private String name;\n    private  Integer age;\n    private String email;\n}\n<\/code><\/pre>\n<p>3\u3001\u7f16\u5199mapper\u63a5\u53e3<\/p>\n<pre><code class=\"language-java\">package com.atguigu.mapper;\n\nimport com.atguigu.pojo.User;\nimport com.baomidou.mybatisplus.core.mapper.BaseMapper;\n\npublic interface UserMapper extends BaseMapper&lt;User&gt; {\n}<\/code><\/pre>\n<p>4\u3001\u7f16\u5199springboot\u542f\u52a8\u7c7b<\/p>\n<pre><code class=\"language-java\">package com.atguigu;\n\nimport org.mybatis.spring.annotation.MapperScan;\nimport org.springframework.boot.SpringApplication;\nimport org.springframework.boot.autoconfigure.SpringBootApplication;\n\n@SpringBootApplication\n@MapperScan(&quot;com.atguigu.mapper&quot;)\npublic class MainApplication {\n    public static void main(String[] args) {\n        SpringApplication.run(MainApplication.class, args);\n    }\n}<\/code><\/pre>\n<p>5\u3001\u7f16\u5199yaml\u914d\u7f6e\u6587\u4ef6<\/p>\n<pre><code class=\"language-yaml\"># \u8fde\u63a5\u6c60\u914d\u7f6e\nspring:\n  datasource:\n    type: com.alibaba.druid.pool.DruidDataSource\n\n    url: jdbc:mysql:\/\/\/manager\n    username: root\n    password: root\n    driver-class-name: com.mysql.cj.jdbc.Driver\nmybatis-plus:\n  configuration:\n    log-impl: org.apache.ibatis.logging.log4j2.Log4j2Impl<\/code><\/pre>\n<p>6\u3001\u7f16\u5199\u6d4b\u8bd5\u65b9\u6cd5<\/p>\n<pre><code class=\"language-java\">package com.atguigu;\n\nimport com.atguigu.mapper.UserMapper;\nimport com.atguigu.pojo.User;\nimport org.junit.jupiter.api.Test;\nimport org.springframework.beans.factory.annotation.Autowired;\nimport org.springframework.boot.test.context.SpringBootTest;\n\nimport java.util.ArrayList;\nimport java.util.HashMap;\nimport java.util.List;\nimport java.util.Map;\n\n@SpringBootTest\npublic class MybatisPlusTest {\n\n    @Autowired\n    private UserMapper userMapper;\n\n    @Test\n    public void test_insert(){\n        User user = new User();\n        user.setName(&quot;\u5f20\u4e09&quot;);\n        user.setAge(3);\n        user.setEmail(&quot;zhangsan@atguigu.com&quot;);\n        int result = userMapper.insert(user);\n        System.out.println(&quot;result:&quot; + result);\n        System.out.println(&quot;user:&quot; + user);\n    }\n\n    @Test\n    public void test_delete(){\n        \/\/\u6839\u636eid\u5220\u9664\n        int row = userMapper.deleteById(1414782978L);\n\n        System.out.println(&quot;row = &quot; + row);\n\/\/        \u6839\u636eage=20\u5220\u9664\n        Map map = new HashMap();\n        map.put(&quot;age&quot;,20);\n        int i = userMapper.deleteByMap(map);\n        System.out.println(&quot;i = &quot; + i);\n\n\/\/        TODO:wrapper\u6761\u4ef6\u5c01\u88c5\u5bf9\u8c61\uff0c\u65e0\u9650\u7684\u5c01\u88c5\u6761\u4ef6\n    }\n\n\/\/    \u4fee\u6539\n    @Test\n    public void test_update(){\n\/\/        TODO:\u5f53\u5c5e\u6027\u503c\u4e3anull\u7684\u65f6\u5019\uff0c\u4e0d\u4fee\u6539\uff01\n\/\/        user id =1 age \u8be5\u4e3a30\n\/\/        UPDATE user set age =30 where id=1\n        User user = new User();\n        user.setId(1);\n        user.setAge(30);\n\/\/        \u8fd9\u4e2a\u662fuser\u7684\u6267\u884c\u8bed\u53e5\n        int i = userMapper.updateById(user);\n\n\/\/        \u5c06\u6240\u6709\u4eba\u7684\u5e74\u9f84\u6539\u4e3a22\n        User user1 = new User();\n        user.setAge(22);\n        \/\/\u8fd9\u91cc\u7684null\u8868\u793a\u6761\u4ef6\uff0c\u5982\u679c\u4e3anull\uff0c\u5219\u8868\u793a\u66f4\u65b0\u6240\u6709\u6570\u636e\n        int row = userMapper.update(user,null);\n    }\n\n\/\/    \u67e5\u8be2\n    @Test\n    public void test_select(){\n        User user = userMapper.selectById(1);\n        System.out.println(&quot;user = &quot; + user);\n\n\/\/        ids\u96c6\u5408\u67e5\u8be2\n        List&lt;Long&gt; ids = new ArrayList&lt;&gt;();\n        ids.add(1L);\n        ids.add(2L);\n        List&lt;User&gt; userList = userMapper.selectBatchIds(ids);\n        System.out.println(&quot;userList = &quot; + userList);\n\n    }\n}\n<\/code><\/pre>\n<h2>2\u3001\u57fa\u4e8eService\u63a5\u53e3\u7684CRUD<\/h2>\n<h3>1\u3001\u4ecb\u7ecd<\/h3>\n<p>1\u3001\u57fa\u4e8eService\uff0c\u66f4\u591a\u7684\u662f\u4f1a\u7275\u626f\u5230\u4e00\u70b9\u4e1a\u52a1<\/p>\n<p>2\u3001\u901a\u7528 Service CRUD \u5c01\u88c5<a href=\"https:\/\/gitee.com\/baomidou\/mybatis-plus\/blob\/3.0\/mybatis-plus-extension\/src\/main\/java\/com\/baomidou\/mybatisplus\/extension\/service\/IService.java\">IService (opens new window)<\/a>\u63a5\u53e3\uff0c\u8fdb\u4e00\u6b65\u5c01\u88c5 CRUD \u91c7\u7528 <code>get \u67e5\u8be2\u5355\u884c<\/code> <code>remove \u5220\u9664<\/code> <code>list \u67e5\u8be2\u96c6\u5408<\/code> <code>page \u5206\u9875<\/code> \u524d\u7f00\u547d\u540d\u65b9\u5f0f\u533a\u5206 <code>Mapper<\/code> \u5c42\u907f\u514d\u6df7\u6dc6\uff0c<\/p>\n<p>3\u3001\u4e0d\u4f1a\u53ef\u4ee5\u67e5\u6587\u6863<\/p>\n<h3>2\u3001\u5bf9\u6bd4Mapper\u63a5\u53e3CRUD\u533a\u522b\uff1a<\/h3>\n<p>1\u3001Service\u6dfb\u52a0\u4e86\u6279\u91cf\u65b9\u6cd5<\/p>\n<p>2\u3001Service\u5c42\u7684\u65b9\u6cd5\u81ea\u52a8\u6dfb\u52a0\u4e86\u4e8b\u52a1<\/p>\n<h3>3\u3001\u4f7f\u7528Iservice\u63a5\u53e3\u65b9\u5f0f<\/h3>\n<h4>1\u3001\u63a5\u53e3\u7ee7\u627fIService\u63a5\u53e3<\/h4>\n<p>1\u3001\u6211\u4eec\u81ea\u5df1\u5199\u7684Service\u63a5\u53e3\uff0c\u7ee7\u627fIService\u8fd9\u4e2a\u63a5\u53e3<\/p>\n<ul>\n<li>\u8fd9\u91cc\u7ee7\u627f\u4e86\u8fd9\u4e2a\u63a5\u53e3\uff0c\u76f8\u5f53\u4e8e\u53ea\u5b9e\u73b0\u4e86\u63a5\u53e3\u4e2d\u4e00\u534a\u7684\u65b9\u6cd5\uff0c\u53e6\u5916\u4e00\u534a\u5728\u5b9e\u73b0\u7c7b\u4e2d\u3002<\/li>\n<li>\u8fd9\u662fSpring\u5f04\u7684<\/li>\n<\/ul>\n<p>2\u3001\u5b9e\u73b0<\/p>\n<pre><code class=\"language-java\">package com.atguigu.service;\n\nimport com.atguigu.pojo.User;\nimport com.baomidou.mybatisplus.extension.service.IService;\n\n\/\/\u7ee7\u627f\u8fd9\u4e2a\u53ea\u5b9e\u73b0\u4e86\u4e00\u534a\u7684\u65b9\u6cd5\uff0c\u53e6\u5916\u4e00\u534a\u5728\u5b9e\u73b0\u7c7b\u4e2d\npublic interface UserService extends IService&lt;User&gt; {\n}\n<\/code><\/pre>\n<h4>2\u3001\u7c7b\u7ee7\u627fServiceImpl\u5b9e\u73b0\u7c7b<\/h4>\n<p>1\u3001\u5c31\u662f\u6211\u4eec\u5199\u7684ServiceImpl\u53bb\u5b9e\u73b0\u7cfb\u7edf\u7684ServiceImpl<\/p>\n<ul>\n<li>\u56e0\u4e3a\u53e6\u5916\u4e00\u534a\u7684\u5b9e\u73b0\u7c7b\u5c31\u5728\u8fd9\u4e2aServiceImpl\u4e2d<\/li>\n<\/ul>\n<p>2\u3001\u5b9e\u73b0<\/p>\n<pre><code class=\"language-java\">package com.atguigu.service.impl;\n\nimport com.atguigu.mapper.UserMapper;\nimport com.atguigu.pojo.User;\nimport com.atguigu.service.UserService;\nimport com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;\nimport org.springframework.stereotype.Service;\n\n\/\/\u8fd9\u4e2a\u5c31\u662f\u5b9e\u73b0\u53e6\u5916\u4e00\u534a\u65b9\u6cd5\n@Service\npublic class UserServiceImpl extends ServiceImpl&lt;UserMapper, User&gt; implements UserService {\n}\n<\/code><\/pre>\n<h3>4\u3001CRUD\u65b9\u6cd5<\/h3>\n<p>1\u3001\u8fd9\u4e9b\u90fd\u662fmybatis-plus\u5199\u597d\u7684\u3002\u6211\u4eec\u76f4\u63a5\u7528\uff0c\u4f1a\u7528\u5c31\u884c<\/p>\n<h4>1\u3001\u4fdd\u5b58\uff08save\uff09<\/h4>\n<pre><code class=\"language-java\">\/\/ \u63d2\u5165\u4e00\u6761\u8bb0\u5f55\uff08\u9009\u62e9\u5b57\u6bb5\uff0c\u7b56\u7565\u63d2\u5165\uff09\nboolean save(T entity);\n\/\/ \u63d2\u5165\uff08\u6279\u91cf\uff09\nboolean saveBatch(Collection&lt;T&gt; entityList);\n\/\/ \u63d2\u5165\uff08\u6279\u91cf\uff09\nboolean saveBatch(Collection&lt;T&gt; entityList, int batchSize);<\/code><\/pre>\n<h4>2\u3001\u4fee\u6539\u6216\u4fdd\u5b58\uff08saveOrUpdate)<\/h4>\n<pre><code class=\"language-java\">\/\/ TableId \u6ce8\u89e3\u5b58\u5728\u66f4\u65b0\u8bb0\u5f55\uff0c\u5426\u63d2\u5165\u4e00\u6761\u8bb0\u5f55\nboolean saveOrUpdate(T entity);\n\/\/ \u6839\u636eupdateWrapper\u5c1d\u8bd5\u66f4\u65b0\uff0c\u5426\u7ee7\u7eed\u6267\u884csaveOrUpdate(T)\u65b9\u6cd5\nboolean saveOrUpdate(T entity, Wrapper&lt;T&gt; updateWrapper);\n\/\/ \u6279\u91cf\u4fee\u6539\u63d2\u5165\nboolean saveOrUpdateBatch(Collection&lt;T&gt; entityList);\n\/\/ \u6279\u91cf\u4fee\u6539\u63d2\u5165\nboolean saveOrUpdateBatch(Collection&lt;T&gt; entityList, int batchSize);<\/code><\/pre>\n<h4>3\u3001\u79fb\u9664\uff08remove\uff09<\/h4>\n<pre><code class=\"language-java\">\/\/ \u6839\u636e queryWrapper \u8bbe\u7f6e\u7684\u6761\u4ef6\uff0c\u5220\u9664\u8bb0\u5f55\nboolean remove(Wrapper&lt;T&gt; queryWrapper);\n\/\/ \u6839\u636e ID \u5220\u9664\nboolean removeById(Serializable id);\n\/\/ \u6839\u636e columnMap \u6761\u4ef6\uff0c\u5220\u9664\u8bb0\u5f55\nboolean removeByMap(Map&lt;String, Object&gt; columnMap);\n\/\/ \u5220\u9664\uff08\u6839\u636eID \u6279\u91cf\u5220\u9664\uff09\nboolean removeByIds(Collection&lt;? extends Serializable&gt; idList);<\/code><\/pre>\n<h4>4\u3001\u66f4\u65b0\uff08Update\uff09<\/h4>\n<pre><code class=\"language-java\">\/\/ \u6839\u636e UpdateWrapper \u6761\u4ef6\uff0c\u66f4\u65b0\u8bb0\u5f55 \u9700\u8981\u8bbe\u7f6esqlset\nboolean update(Wrapper&lt;T&gt; updateWrapper);\n\/\/ \u6839\u636e whereWrapper \u6761\u4ef6\uff0c\u66f4\u65b0\u8bb0\u5f55\nboolean update(T updateEntity, Wrapper&lt;T&gt; whereWrapper);\n\/\/ \u6839\u636e ID \u9009\u62e9\u4fee\u6539\nboolean updateById(T entity);\n\/\/ \u6839\u636eID \u6279\u91cf\u66f4\u65b0\nboolean updateBatchById(Collection&lt;T&gt; entityList);\n\/\/ \u6839\u636eID \u6279\u91cf\u66f4\u65b0\nboolean updateBatchById(Collection&lt;T&gt; entityList, int batchSize);<\/code><\/pre>\n<h4>5\u3001\u6570\u91cf\uff08count\uff09<\/h4>\n<pre><code class=\"language-java\">\/\/ \u67e5\u8be2\u603b\u8bb0\u5f55\u6570\nint count();\n\/\/ \u6839\u636e Wrapper \u6761\u4ef6\uff0c\u67e5\u8be2\u603b\u8bb0\u5f55\u6570\nint count(Wrapper&lt;T&gt; queryWrapper);<\/code><\/pre>\n<h4>6\u3001\u67e5\u8be2\uff08Select\uff09<\/h4>\n<pre><code class=\"language-java\">\/\/ \u6839\u636e ID \u67e5\u8be2\nT getById(Serializable id);\n\/\/ \u6839\u636e Wrapper\uff0c\u67e5\u8be2\u4e00\u6761\u8bb0\u5f55\u3002\u7ed3\u679c\u96c6\uff0c\u5982\u679c\u662f\u591a\u4e2a\u4f1a\u629b\u51fa\u5f02\u5e38\uff0c\u968f\u673a\u53d6\u4e00\u6761\u52a0\u4e0a\u9650\u5236\u6761\u4ef6 wrapper.last(&quot;LIMIT 1&quot;)\nT getOne(Wrapper&lt;T&gt; queryWrapper);\n\/\/ \u6839\u636e Wrapper\uff0c\u67e5\u8be2\u4e00\u6761\u8bb0\u5f55\nT getOne(Wrapper&lt;T&gt; queryWrapper, boolean throwEx);\n\/\/ \u6839\u636e Wrapper\uff0c\u67e5\u8be2\u4e00\u6761\u8bb0\u5f55\nMap&lt;String, Object&gt; getMap(Wrapper&lt;T&gt; queryWrapper);\n\/\/ \u6839\u636e Wrapper\uff0c\u67e5\u8be2\u4e00\u6761\u8bb0\u5f55\n&lt;V&gt; V getObj(Wrapper&lt;T&gt; queryWrapper, Function&lt;? super Object, V&gt; mapper);<\/code><\/pre>\n<h4>7\u3001\u96c6\u5408\uff08List\uff09<\/h4>\n<pre><code class=\"language-java\">\/\/ \u67e5\u8be2\u6240\u6709\nList&lt;T&gt; list();\n\/\/ \u67e5\u8be2\u5217\u8868\nList&lt;T&gt; list(Wrapper&lt;T&gt; queryWrapper);\n\/\/ \u67e5\u8be2\uff08\u6839\u636eID \u6279\u91cf\u67e5\u8be2\uff09\nCollection&lt;T&gt; listByIds(Collection&lt;? extends Serializable&gt; idList);\n\/\/ \u67e5\u8be2\uff08\u6839\u636e columnMap \u6761\u4ef6\uff09\nCollection&lt;T&gt; listByMap(Map&lt;String, Object&gt; columnMap);\n\/\/ \u67e5\u8be2\u6240\u6709\u5217\u8868\nList&lt;Map&lt;String, Object&gt;&gt; listMaps();\n\/\/ \u67e5\u8be2\u5217\u8868\nList&lt;Map&lt;String, Object&gt;&gt; listMaps(Wrapper&lt;T&gt; queryWrapper);\n\/\/ \u67e5\u8be2\u5168\u90e8\u8bb0\u5f55\nList&lt;Object&gt; listObjs();\n\/\/ \u67e5\u8be2\u5168\u90e8\u8bb0\u5f55\n&lt;V&gt; List&lt;V&gt; listObjs(Function&lt;? super Object, V&gt; mapper);\n\/\/ \u6839\u636e Wrapper \u6761\u4ef6\uff0c\u67e5\u8be2\u5168\u90e8\u8bb0\u5f55\nList&lt;Object&gt; listObjs(Wrapper&lt;T&gt; queryWrapper);\n\/\/ \u6839\u636e Wrapper \u6761\u4ef6\uff0c\u67e5\u8be2\u5168\u90e8\u8bb0\u5f55\n&lt;V&gt; List&lt;V&gt; listObjs(Wrapper&lt;T&gt; queryWrapper, Function&lt;? super Object, V&gt; mapper);<\/code><\/pre>\n<h3>5\u3001\u4f8b\u5b50<\/h3>\n<h4>1\u3001\u6b65\u9aa4<\/h4>\n<p>1\u3001\u521b\u5efa\u9879\u76ee<\/p>\n<p>2\u3001\u5bfc\u5165\u4f9d\u8d56<\/p>\n<p>3\u3001\u7f16\u5199\u5b9e\u4f53\u7c7b<\/p>\n<p>4\u3001\u7f16\u5199mapper\u63a5\u53e3<\/p>\n<p>5\u3001\u7f16\u5199Service\u63a5\u53e3<\/p>\n<p>6\u3001\u7f16\u5199ServiceImpl\u5b9e\u73b0\u7c7b<\/p>\n<p>7\u3001\u7f16\u5199\u542f\u52a8\u7c7b<\/p>\n<p>8\u3001\u7f16\u5199yaml\u914d\u7f6e\u6587\u4ef6<\/p>\n<p>9\u3001\u7f16\u5199\u6d4b\u8bd5\u65b9\u6cd5<\/p>\n<h4>2\u3001\u5b9e\u73b0<\/h4>\n<p>1\u3001\u4f9d\u8d56\u548c\u4e0a\u9762\u4e00\u6837<\/p>\n<p>2\u3001\u7f16\u5199\u5b9e\u4f53\u7c7b<\/p>\n<pre><code class=\"language-java\">package com.atguigu.pojo;\n\nimport lombok.Data;\n\n@Data\npublic class User {\n    private Integer id;\n    private String name;\n    private  Integer age;\n    private String email;\n}\n<\/code><\/pre>\n<p>3\u3001\u7f16\u5199mapper\u63a5\u53e3<\/p>\n<pre><code class=\"language-java\">package com.atguigu.mapper;\n\nimport com.atguigu.pojo.User;\nimport com.baomidou.mybatisplus.core.mapper.BaseMapper;\n\npublic interface UserMapper extends BaseMapper&lt;User&gt; {\n}\n<\/code><\/pre>\n<p>4\u3001\u7f16\u5199Service\u63a5\u53e3<\/p>\n<pre><code class=\"language-java\">package com.atguigu.service;\n\nimport com.atguigu.pojo.User;\nimport com.baomidou.mybatisplus.extension.service.IService;\n\n\/\/\u7ee7\u627f\u8fd9\u4e2a\u53ea\u5b9e\u73b0\u4e86\u4e00\u534a\u7684\u65b9\u6cd5\uff0c\u53e6\u5916\u4e00\u534a\u5728\u5b9e\u73b0\u7c7b\u4e2d\npublic interface UserService extends IService&lt;User&gt; {\n}\n<\/code><\/pre>\n<p>5\u3001\u7f16\u5199ServiceImpl\u5b9e\u73b0\u7c7b<\/p>\n<pre><code class=\"language-java\">package com.atguigu.service.impl;\n\nimport com.atguigu.mapper.UserMapper;\nimport com.atguigu.pojo.User;\nimport com.atguigu.service.UserService;\nimport com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;\nimport org.springframework.stereotype.Service;\n\n\/\/\u8fd9\u4e2a\u5c31\u662f\u5b9e\u73b0\u53e6\u5916\u4e00\u534a\u65b9\u6cd5\n@Service\npublic class UserServiceImpl extends ServiceImpl&lt;UserMapper, User&gt; implements UserService {\n}\n<\/code><\/pre>\n<p>6\u3001\u7f16\u5199springboot\u542f\u52a8\u7c7b<\/p>\n<pre><code class=\"language-java\">package com.atguigu;\n\nimport org.mybatis.spring.annotation.MapperScan;\nimport org.springframework.boot.SpringApplication;\nimport org.springframework.boot.autoconfigure.SpringBootApplication;\n\n@SpringBootApplication\n@MapperScan(&quot;com.atguigu.mapper&quot;)\npublic class MainApplication {\n    public static void main(String[] args) {\n        SpringApplication.run(MainApplication.class, args);\n    }\n}\n<\/code><\/pre>\n<p>7\u3001\u7f16\u5199yaml\u914d\u7f6e\u6587\u4ef6<\/p>\n<pre><code class=\"language-java\"># \u8fde\u63a5\u6c60\u914d\u7f6e\nspring:\n  datasource:\n    type: com.alibaba.druid.pool.DruidDataSource\n\n    url: jdbc:mysql:\/\/\/manager\n    username: root\n    password: root\n    driver-class-name: com.mysql.cj.jdbc.Driver\nmybatis-plus:\n  configuration:\n    log-impl: org.apache.ibatis.logging.log4j2.Log4j2Impl<\/code><\/pre>\n<p>8\u3001\u7f16\u5199\u6d4b\u8bd5\u7c7b<\/p>\n<pre><code class=\"language-java\">package com.atguigu;\n\nimport com.atguigu.pojo.User;\nimport com.atguigu.service.UserService;\nimport org.junit.jupiter.api.Test;\nimport org.springframework.beans.factory.annotation.Autowired;\nimport org.springframework.boot.test.context.SpringBootTest;\n\nimport java.security.Provider;\nimport java.util.ArrayList;\nimport java.util.List;\n\n@SpringBootTest\npublic class MybatisPlusTest {\n\n    @Autowired\n    private UserService service;\n\n    @Test\n    public void test_save(){\n        List&lt;User&gt; list = new ArrayList&lt;&gt;();\n        User user = new User();\n        user.setAge(20);\n        user.setName(&quot;\u5f20\u4e09&quot;);\n        user.setEmail(&quot;zhangsan@qq.com&quot;);\n        list.add(user);\n\n        User user1 = new User();\n        user1.setAge(21);\n        user1.setName(&quot;\u674e\u56db&quot;);\n        user1.setEmail(&quot;lisi@qq.com&quot;);\n        list.add(user1);\n\n        boolean b = service.saveBatch(list);\n        System.out.println(&quot;b = &quot; + b);\n    }\n\n    @Test\n    public void test_update(){\n        User user = new User();\n\n        user.setName(&quot;\u738b\u4e94&quot;);\n        user.setEmail(&quot;wangwu@qq.com&quot;);\n        boolean b = service.saveOrUpdate(user);\n        System.out.println(&quot;b = &quot; + b);\n    }\n    @Test\n    public void test_delete(){\n        boolean b = service.removeById(-1777090559);\n        System.out.println(&quot;b = &quot; + b);\n    }\n\n    @Test\n    public void test_select(){\n\/\/        get\u8fd4\u56de\u5355\u4e2a\u5bf9\u8c61\n        User byId =  service.getById(1L);\n        System.out.println(&quot;byId = &quot; + byId);\n\/\/        \u67e5\u8be2\u5168\u90e8\uff0c\u8fd4\u56de\u7684\u96c6\u5408\n        List&lt;User&gt; list = service.list(null);\n        System.out.println(&quot;list = &quot; + list);\n    }\n}<\/code><\/pre>\n<h2>3\u3001\u5206\u9875\u67e5\u8be2<\/h2>\n<h3>1\u3001\u6b65\u9aa4<\/h3>\n<p>1\u3001\u5bfc\u5165\u5206\u9875\u63d2\u4ef6<\/p>\n<ul>\n<li>\u5728\u542f\u52a8\u7c7b\u4e2d\u5199\uff0c\u7136\u540e\u6ce8\u5165ioc\u5bb9\u5668<\/li>\n<\/ul>\n<p>2\u3001\u4f7f\u7528\u5206\u9875\u63d2\u4ef6<\/p>\n<p>3\u3001\u4e5f\u53ef\u4ee5\u81ea\u5b9a\u4e49\u5206\u9875\u63d2\u4ef6<\/p>\n<h3>2\u3001\u5b9e\u73b0<\/h3>\n<p>1\u3001\u5bfc\u5165\u5206\u9875\u63d2\u4ef6<\/p>\n<pre><code class=\"language-java\">@Bean\npublic MybatisPlusInterceptor mybatisPlusInterceptor() {\n    MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();\n    interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));\n    return interceptor;\n}<\/code><\/pre>\n<p>2\u3001\u4f7f\u7528\u5206\u9875\u63d2\u4ef6<\/p>\n<pre><code class=\"language-java\">package com.atguigu;\nimport com.atguigu.mapper.UserMapper;\nimport com.atguigu.pojo.User;\nimport com.baomidou.mybatisplus.extension.plugins.pagination.Page;\nimport org.junit.jupiter.api.Test;\nimport org.springframework.beans.factory.annotation.Autowired;\nimport org.springframework.boot.test.context.SpringBootTest;\n\nimport java.util.List;\n\n@SpringBootTest\npublic class test {\n    @Autowired\n    private UserMapper userMapper;\n    @Test\n    public void testPage(){\n\/\/        IPage\u63a5\u53e3\uff0c\u9700\u8981Page\u5b9e\u73b0\u7c7b\u3010\u9875\u7801\uff0c\u9875\u5bb9\u91cf\u3011\n        Page&lt;User&gt; page = new Page&lt;&gt;(1,5);\n        Page&lt;User&gt; userPage = userMapper.selectPage(page, null);\n        System.out.println(&quot;userPage = &quot; + userPage);\n\n\/\/        \u7ed3\u679cpage\u6700\u540e\u4e5f\u4f1a\u5c01\u88c5\u7ed3\u679c\n        long current = page.getCurrent();\n        System.out.println(&quot;\u5f53\u524d\u9875\u7801\uff1a&quot;+current);\n        long size = page.getSize();\n        System.out.println(&quot;\u6bcf\u9875\u663e\u793a\u6570\uff1a&quot;+size);\n        long total = page.getTotal();\/\/\u603b\u6761\u6570\n        System.out.println(&quot;total = &quot; + total);\n        List&lt;User&gt; records = page.getRecords();\n        System.out.println(&quot;records = &quot; + records);\n\n    }\n}<\/code><\/pre>\n<h4>3\u3001\u81ea\u5b9a\u4e49\u5206\u9875\u63d2\u4ef6<\/h4>\n<p>1\u3001\u65b9\u6cd5<\/p>\n<pre><code class=\"language-java\">package com.atguigu.mapper;\n\nimport com.atguigu.pojo.User;\nimport com.baomidou.mybatisplus.core.mapper.BaseMapper;\nimport com.baomidou.mybatisplus.core.metadata.IPage;\nimport org.apache.ibatis.annotations.Param;\n\npublic  interface UserMapper extends  BaseMapper&lt;User&gt; {\n\n    \/\/    \u5b9a\u4e49\u4e00\u4e2a\u6839\u636e\u5e74\u9f84\u53c2\u6570\u67e5\u8be2\uff0c\u5e76\u4e14\u5206\u9875\u7684\u65b9\u6cd5 age&gt;xx\n    public IPage&lt;User&gt; queryByAge(IPage&lt;User&gt; page, @Param(&quot;age&quot;) Integer age);\n}\n<\/code><\/pre>\n<p>2\u3001\u63a5\u53e3\u5b9e\u73b0xml<\/p>\n<pre><code class=\"language-xml\">&lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot; ?&gt;\n&lt;!DOCTYPE mapper\n        PUBLIC &quot;-\/\/mybatis.org\/\/DTD Mapper 3.0\/\/EN&quot;\n        &quot;https:\/\/mybatis.org\/dtd\/mybatis-3-mapper.dtd&quot;&gt;\n&lt;!-- namespace\u7b49\u4e8emapper\u63a5\u53e3\u7c7b\u7684\u5168\u9650\u5b9a\u540d,\u8fd9\u6837\u5b9e\u73b0\u5bf9\u5e94 --&gt;\n&lt;mapper namespace=&quot;com.atguigu.mapper.UserMapper&quot;&gt;\n\n&lt;!--    \u65b9\u6cd5\uff0c\u5199\u7684\u662f\u67e5\u8be2\u96c6\u5408\u6cdb\u578b\uff0cpage\u7684\u6cdb\u578b--&gt;\n    &lt;select id=&quot;queryByAge&quot; resultType=&quot;user&quot;&gt;\n        select * from user where age &gt; #{age}\n    &lt;\/select&gt;\n&lt;\/mapper&gt;<\/code><\/pre>\n<p>3\u3001\u8fdb\u884c\u6d4b\u8bd5<\/p>\n<pre><code class=\"language-java\"> @Test\n    public void testPage1(){\n\/\/        IPage\u63a5\u53e3\uff0c\u9700\u8981Page\u5b9e\u73b0\u7c7b\u3010\u9875\u7801\uff0c\u9875\u5bb9\u91cf\u3011\n        Page&lt;User&gt; page = new Page&lt;&gt;(1,5);\n        userMapper.queryByAge(page,null);\n        Page&lt;User&gt; userPage = userMapper.selectPage(page, null);\n        System.out.println(&quot;userPage = &quot; + userPage);\n\/\/        \u7ed3\u679cpage\u6700\u540e\u4e5f\u4f1a\u5c01\u88c5\u7ed3\u679c\n        long current = page.getCurrent();\n        System.out.println(&quot;\u5f53\u524d\u9875\u7801\uff1a&quot;+current);\n        long size = page.getSize();\n        System.out.println(&quot;\u6bcf\u9875\u663e\u793a\u6570\uff1a&quot;+size);\n        long total = page.getTotal();\/\/\u603b\u6761\u6570\n        System.out.println(&quot;total = &quot; + total);\n        List&lt;User&gt; records = page.getRecords();\n        System.out.println(&quot;records = &quot; + records);\n    }<\/code><\/pre>\n<h2>4\u3001\u6761\u4ef6\u6784\u9020\u5668Wrapper<\/h2>\n<h3>1\u3001\u4f5c\u7528<\/h3>\n<p>1\u3001\u4f7f\u7528MyBatis-Plus\u7684\u6761\u4ef6\u6784\u9020\u5668\uff0c\u4f60\u53ef\u4ee5\u6784\u5efa\u7075\u6d3b\u3001\u9ad8\u6548\u7684\u67e5\u8be2\u6761\u4ef6\uff0c\u800c\u4e0d\u9700\u8981\u624b\u52a8\u7f16\u5199\u590d\u6742\u7684 SQL \u8bed\u53e5\u3002<\/p>\n<p>2\u3001\u5b83\u63d0\u4f9b\u4e86\u8bb8\u591a\u65b9\u6cd5\u6765\u652f\u6301\u5404\u79cd\u6761\u4ef6\u64cd\u4f5c\u7b26\uff0c\u5e76\u4e14\u53ef\u4ee5\u901a\u8fc7\u94fe\u5f0f\u8c03\u7528\u6765\u7ec4\u5408\u591a\u4e2a\u6761\u4ef6\u3002<\/p>\n<p>3\u3001\u8fd9\u6837\u53ef\u4ee5\u7b80\u5316\u67e5\u8be2\u7684\u7f16\u5199\u8fc7\u7a0b\uff0c\u5e76\u63d0\u9ad8\u5f00\u53d1\u6548\u7387\u3002<\/p>\n<p>4\u3001\u4f8b\u5b50<\/p>\n<pre><code class=\"language-java\">QueryWrapper&lt;User&gt; queryWrapper = new QueryWrapper&lt;&gt;();\nqueryWrapper.eq(&quot;name&quot;, &quot;John&quot;); \/\/ \u6dfb\u52a0\u7b49\u4e8e\u6761\u4ef6\nqueryWrapper.ne(&quot;age&quot;, 30); \/\/ \u6dfb\u52a0\u4e0d\u7b49\u4e8e\u6761\u4ef6\nqueryWrapper.like(&quot;email&quot;, &quot;@gmail.com&quot;); \/\/ \u6dfb\u52a0\u6a21\u7cca\u5339\u914d\u6761\u4ef6\n\u7b49\u540c\u4e8e\uff1a \ndelete from user where name = &quot;John&quot; and age != 30\n                                  and email like &quot;%@gmail.com%&quot;\n\/\/ \u6839\u636e entity \u6761\u4ef6\uff0c\u5220\u9664\u8bb0\u5f55\nint delete(@Param(Constants.WRAPPER) Wrapper&lt;T&gt; wrapper);<\/code><\/pre>\n<h3>2\u3001\u6761\u4ef6\u6784\u9020\u5668\u7684\u7ee7\u627f\u7ed3\u6784<\/h3>\n<p>1\u3001\u7ed3\u6784\u56fe<\/p>\n<p><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/zyg.luchers.cn\/wp-content\/uploads\/2024\/04\/image-20240123125910705.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/zyg.luchers.cn\/wp-content\/uploads\/2024\/04\/image-20240123125910705.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"image-20240123125910705\" \/><\/div><\/p>\n<p>2\u3001Wrapper\u6761\u4ef6\u6784\u9020\u62bd\u8c61\u7c7b\uff0c\u662f\u9876\u7ea7\u7236\u7c7b<\/p>\n<p>3\u3001\u89e3\u91ca<\/p>\n<ul>\n<li>AbstractWrapper \uff1a \u7528\u4e8e\u67e5\u8be2\u6761\u4ef6\u5c01\u88c5\uff0c\u751f\u6210 sql \u7684 where \u6761\u4ef6\n<ul>\n<li>QueryWrapper \uff1a \u67e5\u8be2\/\u5220\u9664\u6761\u4ef6\u5c01\u88c5<\/li>\n<li>UpdateWrapper \uff1a \u4fee\u6539\u6761\u4ef6\u5c01\u88c5<\/li>\n<li>AbstractLambdaWrapper \uff1a \u4f7f\u7528Lambda \u8bed\u6cd5<\/li>\n<li>LambdaQueryWrapper \uff1a\u7528\u4e8eLambda\u8bed\u6cd5\u4f7f\u7528\u7684\u67e5\u8be2Wrapper<\/li>\n<li>LambdaUpdateWrapper \uff1a Lambda \u66f4\u65b0\u5c01\u88c5Wrapper<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h3>3\u3001\u57fa\u4e8eQueryWrapper\u7ec4\u88c5\u6761\u4ef6<\/h3>\n<p>1\u3001\u53ef\u4ee5\u5728\u5b98\u65b9\u6587\u6863\u4e0a\u67e5\u770b<\/p>\n<p>2\u3001<div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/zyg.luchers.cn\/wp-content\/uploads\/2024\/04\/image-20240123130138323.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/zyg.luchers.cn\/wp-content\/uploads\/2024\/04\/image-20240123130138323.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"image-20240123130138323\" \/><\/div><\/p>\n<h4>3\u3001\u4f8b\u5b50<\/h4>\n<h5>1\u3001\u6b65\u9aa4<\/h5>\n<p>1\u3001\u6570\u636e\u5e93<\/p>\n<p>2\u3001\u5b9e\u4f53\u7c7b<\/p>\n<p>3\u3001userMapper\u63a5\u53e3<\/p>\n<p>4\u3001\u6d4b\u8bd5\u65b9\u6cd5<\/p>\n<h5>2\u3001\u5b9e\u73b0<\/h5>\n<p>1\u3001\u6570\u636e\u5e93\u548c\u4e4b\u524d\u4e00\u6837<\/p>\n<p>2\u3001\u5b9e\u4f53\u7c7b<\/p>\n<pre><code class=\"language-java\">package com.atguigu.pojo;\n\nimport com.baomidou.mybatisplus.annotation.TableName;\nimport lombok.Data;\n\n\/**\n * @TableName(&quot;user&quot;)\u8fd9\u4e2a\u6ce8\u89e3\u53ef\u4ee5\u4e0d\u52a0\n *  \u76f4\u63a5\u4f7f\u7528\u5b9e\u4f53\u7c7b\u7684\u540d\u5b57\u4f5c\u4e3a\u6570\u636e\u5e93\u7684\u8868\u540d\n *  \u5ffd\u7565\u5927\u5c0f\u5199\n *  \u5f53\u6570\u636e\u5e93\u7684\u8868\u540d\u4e0e\u5b9e\u4f53\u7c7b\u547d\u540d\u4e0d\u540c\uff08\u5ffd\u7565\u5927\u5c0f\u5199\uff09\u4f7f\u7528@TableName()\u6765\u6307\u5b9a\u8868\u540d\n *  \u8fd9\u4e2a\u662f\u5355\u4e2a\u4fee\u6539\uff0c\u4e07\u4e00\u6709\u5f88\u591a\u4e2a\u5b9e\u4f53\u7c7b\u9700\u8981\u4fee\u6539\u6210t_\u5f00\u5934\u5462\u3002\n *\/\n\n@TableName(&quot;user&quot;)\n@Data\npublic class User {\n    private Integer id;\n    private String name;\n    private  Integer age;\n    private String email;\n}\n<\/code><\/pre>\n<p>3\u3001UserMapper\u63a5\u53e3\u7c7b<\/p>\n<pre><code class=\"language-java\">package com.atguigu.mapper;\n\nimport com.atguigu.pojo.User;\nimport com.baomidou.mybatisplus.core.mapper.BaseMapper;\nimport com.baomidou.mybatisplus.core.metadata.IPage;\nimport org.apache.ibatis.annotations.Param;\n\npublic  interface UserMapper extends  BaseMapper&lt;User&gt; {\n\n    \/\/    \u5b9a\u4e49\u4e00\u4e2a\u6839\u636e\u5e74\u9f84\u53c2\u6570\u67e5\u8be2\uff0c\u5e76\u4e14\u5206\u9875\u7684\u65b9\u6cd5 age&gt;xx\n    public IPage&lt;User&gt; queryByAge(IPage&lt;User&gt; page, @Param(&quot;age&quot;) Integer age);\n}\n<\/code><\/pre>\n<p>4\u3001\u6d4b\u8bd5\u65b9\u6cd5<\/p>\n<pre><code class=\"language-java\">package com.atguigu;\n\nimport com.atguigu.mapper.UserMapper;\nimport com.atguigu.pojo.User;\nimport com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;\nimport org.junit.jupiter.api.Test;\nimport org.junit.platform.commons.util.StringUtils;\nimport org.springframework.beans.factory.annotation.Autowired;\nimport org.springframework.boot.test.context.SpringBootTest;\n\nimport java.util.List;\nimport java.util.Map;\n\n@SpringBootTest\npublic class mybatisPlusQueryTest {\n    @Autowired\n    private UserMapper userMapper;\n\n    @Test\n    public void test_01(){\n\/\/        \u67e5\u8be2\u7528\u6237\u540d\u5305\u542ba\uff0c\u5e74\u9f84\u572820\u523030\u4e4b\u95f4\uff0c\u5e76\u4e14\u90ae\u7bb1\u4e0d\u4e3a\u7a7a\n        QueryWrapper&lt;User&gt; queryWrapper = new QueryWrapper&lt;&gt;();\n\/\/        \u7528\u6237\u540d\u5305\u542ba\n        queryWrapper.like(&quot;name&quot;,&quot;a&quot;);\n\/\/        \u5e74\u9f84\u572820\u523030\u4e4b\u95f4\n        queryWrapper.between(&quot;age&quot;,20,30);\n\/\/                \u90ae\u7bb1\u4e0d\u4e3a\u7a7a\n        queryWrapper.isNotNull(&quot;email&quot;);\n\n\/\/        \u94fe\u5f0f\u8c03\u7528\n        queryWrapper.like(&quot;name&quot;,&quot;a&quot;).between(&quot;age&quot;,20,30).isNotNull(&quot;email&quot;);\n\n        List&lt;User&gt; users = userMapper.selectList(queryWrapper);\n\n        System.out.println(&quot;users = &quot; + users);\n    }\n\n    @Test\n    public void test_02(){\n\/\/        \u6309\u5e74\u9f84\u964d\u5e8f\u67e5\u8be2\u7528\u6237\uff0c\u5982\u679c\u5e74\u9f84\u76f8\u540c\u5219\u6309id\u5347\u5e8f\u6392\u5217\n        QueryWrapper&lt;User&gt; queryWrapper = new QueryWrapper&lt;&gt;();\n        queryWrapper.orderByDesc(&quot;age&quot;).orderByAsc(&quot;id&quot;);\n\/\/        order by age desc ,id asc\n        List&lt;User&gt; users = userMapper.selectList(queryWrapper);\n        System.out.println(&quot;users = &quot; + users);\n    }\n\n    @Test\n    public void  test_03(){\n\/\/        \u5220\u9664email\u4e3a\u7a7a\u7684\u7528\u6237\n        QueryWrapper&lt;User&gt; queryWrapper = new QueryWrapper&lt;&gt;();\n        queryWrapper.isNull(&quot;email&quot;);\n        int delete = userMapper.delete(queryWrapper);\n        System.out.println(&quot;delete = &quot; + delete);\n    }\n\n    @Test\n    public void  test_04(){\n\/\/        \u5c06\u5e74\u9f84\u5927\u4e8e20\u5e76\u4e14\u7528\u6237\u4e2d\u5305\u542b\u6709a\u6216\u90ae\u7bb1\u4e3anull\u7684\u7528\u6237\u4fe1\u606f\u4fee\u6539\n        User user = new User();\n        user.setAge(99);\n        user.setName(&quot;hhhhhh&quot;);\n\n\/\/        \u8bbe\u7f6e\u7b5b\u9009\u6761\u4ef6\n        QueryWrapper&lt;User&gt; queryWrapper = new QueryWrapper&lt;&gt;();\n\/\/        \u4ed6\u4eec\u4e4b\u95f4\u7684\u6761\u4ef6\uff0c\u9ed8\u8ba4\u662fand\u3002\u5982\u679c\u8981\u6539\u6210or\u5c31\u9700\u8981\u6dfb\u52a0\u8fd9\u4e2a\u65b9\u6cd5\n        queryWrapper.gt(&quot;age&quot;,20).like(&quot;name&quot;,&quot;a&quot;).or().isNull(&quot;email&quot;);\n        int update = userMapper.update(user, queryWrapper);\n        System.out.println(&quot;update = &quot; + update);\n    }\n\n    @Test\n    public void test_05(){\n\/\/        \u67e5\u8be2\u7528\u6237\u7684\u4fe1\u606fname\u548cage\u5b57\u6bb5,id\u5927\u4e8e1\n        QueryWrapper&lt;User&gt; queryWrapper = new QueryWrapper&lt;&gt;();\n        queryWrapper.gt(&quot;id&quot;,1);\n        queryWrapper.select(&quot;name&quot;,&quot;age&quot;);\n        List&lt;Map&lt;String, Object&gt;&gt; maps = userMapper.selectMaps(queryWrapper);\n        System.out.println(&quot;maps = &quot; + maps);\n\n    }\n\n    @Test\n    public void test_06(){\n\/\/        \u524d\u7aef\u4f20\u5165\u4e86\u4e24\u4e2a\u53c2\u6570 name age\n        String name = &quot;xx&quot;;\n        Integer age = 10;\n        QueryWrapper&lt;User&gt; queryWrapper = new QueryWrapper&lt;&gt;();\n\/\/     TODO:   \u6bcf\u4e2a\u65b9\u6cd5\u4f1a\u6709\u4e00\u4e2aboolean condition\uff0c\u5141\u8bb8\u6211\u4eec\u7b2c\u4e00\u4e2a\u653e\u6bd4\u8f83\u8868\u8fbe\u5f0ftrue\uff0c\u6574\u4e2a\u6761\u4ef6\u751f\u6548\u3002false\u4e0d\u751f\u6548\n\/\/        \u7c7b\u4f3c\u4e8e if test=&quot;\u6761\u4ef6&quot;\n        queryWrapper.eq(StringUtils.isNotBlank(name),&quot;name&quot;,name);\n        queryWrapper.eq(age!=null &amp;&amp; age&gt;18,&quot;age&quot;,age);\n        List&lt;User&gt; list = userMapper.selectList(queryWrapper);\n        System.out.println(&quot;list = &quot; + list);\n    }\n}<\/code><\/pre>\n<h3>4\u3001\u57fa\u4e8eUpdateWrapper\u7ec4\u88c5\u6761\u4ef6<\/h3>\n<h4>1\u3001\u8865\u5145<\/h4>\n<p>1\u3001\u6ce8\u610f\uff1a\u4f7f\u7528queryWrapper + \u5b9e\u4f53\u7c7b\u5f62\u5f0f\u53ef\u4ee5\u5b9e\u73b0\u4fee\u6539\uff0c\u4f46\u662f\u65e0\u6cd5\u5c06\u5217\u503c\u4fee\u6539\u4e3anull\u503c\uff01<\/p>\n<p>2\u3001\u4f46\u662fUpdateWrapper\u53ef\u4ee5\u968f\u610f\u8bbe\u7f6e\u5217\u7684\u503c<\/p>\n<p>3\u3001\u683c\u5f0f<\/p>\n<pre><code>UpdateWrapper\u4fee\u6539\u3010\u6761\u4ef6\uff0c\u4fee\u6539\u3011\n    1\u3001\u76f4\u63a5\u643a\u5e26\u4fee\u6539\u6570\u636eset(&quot;\u5217\u540d&quot;,&quot;\u503c&quot;)\n    2\u3001\u6307\u5b9a\u4efb\u610f\u4fee\u6539\u503cset(&quot;\u5217\u540d&quot;,null)<\/code><\/pre>\n<h4>2\u3001\u5b9e\u73b0<\/h4>\n<pre><code class=\"language-java\">package com.atguigu;\n\nimport com.atguigu.mapper.UserMapper;\nimport com.atguigu.pojo.User;\nimport com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;\nimport com.baomidou.mybatisplus.core.conditions.update.UpdateWrapper;\nimport org.apache.ibatis.annotations.Update;\nimport org.junit.jupiter.api.Test;\nimport org.springframework.beans.factory.annotation.Autowired;\nimport org.springframework.boot.test.context.SpringBootTest;\n\n@SpringBootTest\npublic class MybatisPlusUpdateWrapperTest {\n\n    @Autowired\n    private UserMapper userMapper;\n    @Test\n    public void  test_04(){\n\/\/        \u5c06\u5e74\u9f84\u5927\u4e8e20\u5e76\u4e14\u7528\u6237\u4e2d\u5305\u542b\u6709a\u6216\u90ae\u7bb1\u4e3anull\u7684\u7528\u6237\u4fe1\u606f\u4fee\u6539\n        User user = new User();\n        user.setAge(99);\n        user.setName(&quot;hhhhhh&quot;);\n        user.setEmail(&quot;null&quot;);\n\n\/\/        \u8bbe\u7f6e\u7b5b\u9009\u6761\u4ef6\n        QueryWrapper&lt;User&gt; queryWrapper = new QueryWrapper&lt;&gt;();\n\/\/        \u4ed6\u4eec\u4e4b\u95f4\u7684\u6761\u4ef6\uff0c\u9ed8\u8ba4\u662fand\u3002\u5982\u679c\u8981\u6539\u6210or\u5c31\u9700\u8981\u6dfb\u52a0\u8fd9\u4e2a\u65b9\u6cd5\n        queryWrapper.gt(&quot;age&quot;,20).like(&quot;name&quot;,&quot;a&quot;).or().isNull(&quot;email&quot;);\n        int update = userMapper.update(user, queryWrapper);\n        System.out.println(&quot;update = &quot; + update);\n    }\n\n    @Test\n    public void  test_05(){\n\/\/        \u5c06\u5e74\u9f84\u5927\u4e8e20\u5e76\u4e14\u7528\u6237\u4e2d\u5305\u542b\u6709a\u6216\u90ae\u7bb1\u4e3anull\u7684\u7528\u6237\u4fe1\u606f\u4fee\u6539\n\n        \/*\n        QueryWrapper\u4fee\u6539\u3010\u6761\u4ef6\u3011\n            1\u3001\u8981\u51c6\u5907\u9700\u8981\u4fee\u6539\u7684\u5b9e\u4f53\u7c7b\u6570\u636e\n            2\u3001\u4e0d\u80fd\u4fee\u6539\u4e3anull\n         *\/\n\n        \/*\n        UpdateWrapper\u4fee\u6539\u3010\u6761\u4ef6\uff0c\u4fee\u6539\u3011\n            1\u3001\u76f4\u63a5\u643a\u5e26\u4fee\u6539\u6570\u636eset(&quot;\u5217\u540d&quot;,&quot;\u503c&quot;)\n            2\u3001\u6307\u5b9a\u4efb\u610f\u4fee\u6539\u503cset(&quot;\u5217\u540d&quot;,null)\n         *\/\n\n\/\/        \u8bbe\u7f6e\u7b5b\u9009\u6761\u4ef6\n        UpdateWrapper&lt;User&gt; queryWrapper = new UpdateWrapper&lt;&gt;();\n\/\/        \u4ed6\u4eec\u4e4b\u95f4\u7684\u6761\u4ef6\uff0c\u9ed8\u8ba4\u662fand\u3002\u5982\u679c\u8981\u6539\u6210or\u5c31\u9700\u8981\u6dfb\u52a0\u8fd9\u4e2a\u65b9\u6cd5\n        queryWrapper.gt(&quot;age&quot;,20)\n                .like(&quot;name&quot;,&quot;a&quot;)\n                .or()\n                .isNull(&quot;email&quot;)\n                .set(&quot;email&quot;,null)\n                .set(&quot;age&quot;,99);\n        int update = userMapper.update(null, queryWrapper);\n        System.out.println(&quot;update = &quot; + update);\n\n    }\n}<\/code><\/pre>\n<h3>5\u3001LambdaQueryWrapper\u7ec4\u88c5\u6761\u4ef6<\/h3>\n<p>1\u3001\u76f8\u6bd4\u4e8e QueryWrapper\uff0cLambdaQueryWrapper \u4f7f\u7528\u4e86\u5b9e\u4f53\u7c7b\u7684\u5c5e\u6027\u5f15\u7528\uff08\u4f8b\u5982 User::getName\u3001User::getAge\uff09\uff0c<\/p>\n<p>2\u3001\u800c\u4e0d\u662f\u5b57\u7b26\u4e32\u6765\u8868\u793a\u5b57\u6bb5\u540d\uff0c\u8fd9\u63d0\u9ad8\u4e86\u4ee3\u7801\u7684\u53ef\u8bfb\u6027\u548c\u53ef\u7ef4\u62a4\u6027\u3002<\/p>\n<p>3\u3001\u5bf9\u6bd4\u4f8b\u5b50<\/p>\n<ul>\n<li>\n<p>QueryWrapper\u793a\u4f8b\u4ee3\u7801<\/p>\n<\/li>\n<li>\n<pre><code class=\"language-java\">QueryWrapper<User> queryWrapper = new QueryWrapper<>();\nqueryWrapper.eq(\"name\", \"John\")\n.ge(\"age\", 18)\n.orderByDesc(\"create_time\")\n.last(\"limit 10\");\nList<User> userList = userMapper.selectList(queryWrapper);<\/code><\/pre>\n<\/li>\n<li>\n<p>LambdaQueryWrapper\u793a\u4f8b\u4ee3\u7801<\/p>\n<\/li>\n<li>\n<pre><code class=\"language-java\">LambdaQueryWrapper<User> lambdaQueryWrapper = new LambdaQueryWrapper<>();\n\nlambdaQueryWrapper.eq(User::getName, \"John\")\n.ge(User::getAge, 18)\n.orderByDesc(User::getCreateTime)\n.last(\"limit 10\");\nList<User> userList = userMapper.selectList(lambdaQueryWrapper);<\/code><\/pre>\n<\/li>\n<\/ul>\n<h4>1\u3001lambda\u8868\u8fbe\u5f0f\u56de\u987e<\/h4>\n<h5>1\u3001\u4ecb\u7ecd<\/h5>\n<ul>\n<li>Lambda \u8868\u8fbe\u5f0f\u662f Java 8 \u5f15\u5165\u7684\u4e00\u79cd\u51fd\u6570\u5f0f\u7f16\u7a0b\u7279\u6027\uff0c\u5b83\u63d0\u4f9b\u4e86\u4e00\u79cd\u66f4\u7b80\u6d01\u3001\u66f4\u76f4\u89c2\u7684\u65b9\u5f0f\u6765\u8868\u793a\u533f\u540d\u51fd\u6570\u6216\u51fd\u6570\u5f0f\u63a5\u53e3\u7684\u5b9e\u73b0\u3002<\/li>\n<li>Lambda \u8868\u8fbe\u5f0f\u53ef\u4ee5\u7528\u4e8e\u7b80\u5316\u4ee3\u7801\uff0c\u63d0\u9ad8\u4ee3\u7801\u7684\u53ef\u8bfb\u6027\u548c\u53ef\u7ef4\u62a4\u6027\u3002<\/li>\n<\/ul>\n<h5>2\u3001lambda\u8868\u8fbe\u5f0f\u8bed\u6cd5<\/h5>\n<p>1\u3001\u53c2\u6570\u5217\u8868<\/p>\n<ul>\n<li>\u53c2\u6570\u5217\u8868\u7528\u5c0f\u62ec\u53f7 () \u62ec\u8d77\u6765\uff0c\u53ef\u4ee5\u6307\u5b9a\u96f6\u4e2a\u6216\u591a\u4e2a\u53c2\u6570\u3002\u5982\u679c\u6ca1\u6709\u53c2\u6570\uff0c\u53ef\u4ee5\u7701\u7565\u5c0f\u62ec\u53f7\uff1b\u5982\u679c\u53ea\u6709\u4e00\u4e2a\u53c2\u6570\uff0c\u53ef\u4ee5\u7701\u7565\u5c0f\u62ec\u53f7\u3002<\/li>\n<li>\u793a\u4f8b\uff1a(a, b), x -&gt;, () -&gt;<\/li>\n<\/ul>\n<p>2\u3001\u7bad\u5934\u7b26\u53f7\uff1a<\/p>\n<ul>\n<li>\n<p>\u7bad\u5934\u7b26\u53f7 -&gt; \u5206\u5272\u53c2\u6570\u5217\u8868\u548c Lambda \u8868\u8fbe\u5f0f\u7684\u4e3b\u4f53\u90e8\u5206\u3002<\/p>\n<\/li>\n<li>\n<p>\u793a\u4f8b\uff1a-&gt;<\/p>\n<\/li>\n<\/ul>\n<p>3\u3001Lambda \u8868\u8fbe\u5f0f\u7684\u4e3b\u4f53\uff1a<\/p>\n<ul>\n<li>\n<p>Lambda \u8868\u8fbe\u5f0f\u7684\u4e3b\u4f53\u3002\u5982\u679c\u662f\u4e00\u4e2a\u8868\u8fbe\u5f0f\uff0c\u53ef\u4ee5\u7701\u7565 return \u5173\u952e\u5b57\uff1b<\/p>\n<\/li>\n<li>\n<p>\u5982\u679c\u662f\u591a\u6761\u8bed\u53e5\u7684\u4ee3\u7801\u5757\uff0c\u9700\u8981\u4f7f\u7528\u5927\u62ec\u53f7 <code>{}<\/code> \u62ec\u8d77\u6765\uff0c\u5e76\u4e14\u9700\u8981\u660e\u786e\u6307\u5b9a return \u5173\u952e\u5b57\u3002<\/p>\n<p>\u793a\u4f8b\uff1a<\/p>\n<ul>\n<li>\u5355\u4e2a\u8868\u8fbe\u5f0f\uff1a<code>x -&gt; x * x<\/code><\/li>\n<li>\u4ee3\u7801\u5757\uff1a<code>(x, y) -&gt; { int sum = x + y; return sum; }<\/code><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h5>3\u3001\u5177\u4f53\u4f8b\u5b50<\/h5>\n<pre><code class=\"language-java\">\/\/ \u4f7f\u7528 Lambda \u8868\u8fbe\u5f0f\u5b9e\u73b0\u4e00\u4e2a\u63a5\u53e3\u7684\u65b9\u6cd5\ninterface Greeting {\n    void sayHello();\n}\n\npublic class LambdaExample {\n    public static void main(String[] args) {\n\n        \/\/\u539f\u59cb\u533f\u540d\u5185\u90e8\u7c7b\u65b9\u5f0f\n        Greeting greeting = new Greeting() {\n            @Override\n            public void sayHello(int a) {\n                System.out.println(&quot;Hello, world!&quot;);\n            }\n        };\n\n        a-&gt;System.out.println(&quot;Hello, world!&quot;)\n\n        \/\/ \u4f7f\u7528 Lambda \u8868\u8fbe\u5f0f\u5b9e\u73b0\u63a5\u53e3\u7684\u65b9\u6cd5\n        greeting = () -&gt; System.out.println(&quot;Hello, world!&quot;);\n\n          System.out::println;\n           () -&gt;  \u7c7b.XXX(); -&gt; \u7c7b\uff1a\uff1a\u65b9\u6cd5\u540d\n        \/\/ \u8c03\u7528\u63a5\u53e3\u7684\u65b9\u6cd5\n        greeting.sayHello();\n    }\n}<\/code><\/pre>\n<h4>2\u3001\u65b9\u6cd5\u5f15\u7528<\/h4>\n<h5>1\u3001\u4ecb\u7ecd<\/h5>\n<p>\u65b9\u6cd5\u5f15\u7528\u662f Java 8 \u4e2d\u5f15\u5165\u7684\u4e00\u79cd\u8bed\u6cd5\u7279\u6027\uff0c\u5b83\u63d0\u4f9b\u4e86\u4e00\u79cd\u7b80\u6d01\u7684\u65b9\u5f0f\u6765\u76f4\u63a5\u5f15\u7528\u5df2\u6709\u7684\u65b9\u6cd5\u6216\u6784\u9020\u51fd\u6570\u3002\u65b9\u6cd5\u5f15\u7528\u53ef\u4ee5\u66ff\u4ee3 Lambda \u8868\u8fbe\u5f0f\uff0c\u4f7f\u4ee3\u7801\u66f4\u7b80\u6d01\u3001\u66f4\u6613\u8bfb\u3002<\/p>\n<h5>2\u3001\u683c\u5f0f<\/h5>\n<ol>\n<li><strong>\u9759\u6001\u65b9\u6cd5\u5f15\u7528\uff1a<\/strong> \u5f15\u7528\u9759\u6001\u65b9\u6cd5\uff0c\u8bed\u6cd5\u4e3a <code>\u7c7b\u540d::\u9759\u6001\u65b9\u6cd5\u540d<\/code>\u3002<\/li>\n<li><strong>\u5b9e\u4f8b\u65b9\u6cd5\u5f15\u7528\uff1a<\/strong> \u5f15\u7528\u5b9e\u4f8b\u65b9\u6cd5\uff0c\u8bed\u6cd5\u4e3a <code>\u5b9e\u4f8b\u5bf9\u8c61::\u5b9e\u4f8b\u65b9\u6cd5\u540d<\/code>\u3002<\/li>\n<li><strong>\u5bf9\u8c61\u65b9\u6cd5\u5f15\u7528\uff1a<\/strong> \u5f15\u7528\u7279\u5b9a\u5bf9\u8c61\u7684\u5b9e\u4f8b\u65b9\u6cd5\uff0c\u8bed\u6cd5\u4e3a <code>\u7c7b\u540d::\u5b9e\u4f8b\u65b9\u6cd5\u540d<\/code>\u3002<\/li>\n<li><strong>\u6784\u9020\u51fd\u6570\u5f15\u7528\uff1a<\/strong> \u5f15\u7528\u6784\u9020\u51fd\u6570\uff0c\u8bed\u6cd5\u4e3a <code>\u7c7b\u540d::new<\/code>\u3002<\/li>\n<\/ol>\n<h5>3\u3001\u4f8b\u5b50<\/h5>\n<pre><code class=\"language-java\">@Test\npublic void testQuick4(){\n\n    String name = &quot;root&quot;;\n    int    age = 18;\n\n    QueryWrapper&lt;User&gt; queryWrapper = new QueryWrapper&lt;&gt;();\n    \/\/\u6bcf\u4e2a\u6761\u4ef6\u62fc\u63a5\u65b9\u6cd5\u90fdcondition\u53c2\u6570,\u8fd9\u662f\u4e00\u4e2a\u6bd4\u8f83\u8fd0\u7b97,\u4e3atrue\u8ffd\u52a0\u5f53\u524d\u6761\u4ef6!\n    \/\/eq(condition,\u5217\u540d,\u503c)\n    queryWrapper.eq(!StringUtils.isEmpty(name),&quot;name&quot;,name)\n            .eq(age&gt;1,&quot;age&quot;,age);\n\n    \/\/TODO: \u4f7f\u7528lambdaQueryWrapper\n    LambdaQueryWrapper&lt;User&gt; lambdaQueryWrapper = new LambdaQueryWrapper&lt;&gt;();\n    \/\/\u6ce8\u610f: \u9700\u8981\u4f7f\u7528\u65b9\u6cd5\u5f15\u7528\n    \/\/\u6280\u5de7: \u7c7b\u540d::\u65b9\u6cd5\u540d\n    lambdaQueryWrapper.eq(!StringUtils.isEmpty(name), User::getName,name);\n    List&lt;User&gt; users= userMapper.selectList(lambdaQueryWrapper);\n    System.out.println(users);\n}<\/code><\/pre>\n<h3>6\u3001LambdaUpdateWrapper\u7ec4\u88c5\u6761\u4ef6<\/h3>\n<h4>1\u3001\u5185\u5bb9<\/h4>\n<pre><code class=\"language-java\">\/*\nQueryWrapper\u4fee\u6539\u3010\u6761\u4ef6\u3011\n    1\u3001\u8981\u51c6\u5907\u9700\u8981\u4fee\u6539\u7684\u5b9e\u4f53\u7c7b\u6570\u636e\n    2\u3001\u4e0d\u80fd\u4fee\u6539\u4e3anull\n *\/\n\n\/*\nUpdateWrapper\u4fee\u6539\u3010\u6761\u4ef6\uff0c\u4fee\u6539\u3011\n    1\u3001\u76f4\u63a5\u643a\u5e26\u4fee\u6539\u6570\u636eset(&quot;\u5217\u540d&quot;,&quot;\u503c&quot;)\n    2\u3001\u6307\u5b9a\u4efb\u610f\u4fee\u6539\u503cset(&quot;\u5217\u540d&quot;,null)\n *\/<\/code><\/pre>\n<h4>2\u3001\u683c\u5f0f\u3010\u4f8b\u5b50\u3011<\/h4>\n<p>1\u3001\u76f4\u63a5\u6d4b\u8bd5\u65b9\u6cd5\u3002\u5176\u4ed6\u7684\u548c\u4e0a\u9762\u4e00\u6837\uff0c\u662f\u4e00\u4e2a\u9879\u76ee\u91cc\u7684<\/p>\n<pre><code class=\"language-java\">package com.atguigu;\n\nimport com.atguigu.mapper.UserMapper;\nimport com.atguigu.pojo.User;\nimport com.baomidou.mybatisplus.core.conditions.update.LambdaUpdateWrapper;\nimport com.baomidou.mybatisplus.core.conditions.update.UpdateWrapper;\nimport org.junit.jupiter.api.Test;\nimport org.springframework.beans.factory.annotation.Autowired;\nimport org.springframework.boot.test.context.SpringBootTest;\n\n@SpringBootTest\npublic class MybatisPlusLambdaUpdateWrapperTest {\n    @Autowired\n    private UserMapper userMapper;\n\n    @Test\n    public void  test_05(){\n\/\/        \u5c06\u5e74\u9f84\u5927\u4e8e20\u5e76\u4e14\u7528\u6237\u4e2d\u5305\u542b\u6709a\u6216\u90ae\u7bb1\u4e3anull\u7684\u7528\u6237\u4fe1\u606f\u4fee\u6539\n\n        \/*\n        QueryWrapper\u4fee\u6539\u3010\u6761\u4ef6\u3011\n            1\u3001\u8981\u51c6\u5907\u9700\u8981\u4fee\u6539\u7684\u5b9e\u4f53\u7c7b\u6570\u636e\n            2\u3001\u4e0d\u80fd\u4fee\u6539\u4e3anull\n         *\/\n\n        \/*\n        UpdateWrapper\u4fee\u6539\u3010\u6761\u4ef6\uff0c\u4fee\u6539\u3011\n            1\u3001\u76f4\u63a5\u643a\u5e26\u4fee\u6539\u6570\u636eset(&quot;\u5217\u540d&quot;,&quot;\u503c&quot;)\n            2\u3001\u6307\u5b9a\u4efb\u610f\u4fee\u6539\u503cset(&quot;\u5217\u540d&quot;,null)\n         *\/\n\n\/\/        \u8bbe\u7f6e\u7b5b\u9009\u6761\u4ef6,\u666e\u901a\u65b9\u6cd5\u8868\u8fbe\u5f0f\n        UpdateWrapper&lt;User&gt; queryWrapper = new UpdateWrapper&lt;&gt;();\n\/\/        \u4ed6\u4eec\u4e4b\u95f4\u7684\u6761\u4ef6\uff0c\u9ed8\u8ba4\u662fand\u3002\u5982\u679c\u8981\u6539\u6210or\u5c31\u9700\u8981\u6dfb\u52a0\u8fd9\u4e2a\u65b9\u6cd5\n        queryWrapper.gt(&quot;age&quot;,20)\n                .like(&quot;name&quot;,&quot;a&quot;)\n                .or()\n                .isNull(&quot;email&quot;)\n                .set(&quot;email&quot;,null)\n                .set(&quot;age&quot;,99);\n\n\/\/        lambda\u8868\u8fbe\u5f0f\n        LambdaUpdateWrapper&lt;User&gt; lambdaUpdateWrapper = new LambdaUpdateWrapper&lt;&gt;();\n        lambdaUpdateWrapper.gt(User::getAge,20)\n                .like(User::getName,&quot;a&quot;)\n                .or()\n                .isNull(User::getEmail)\n                .set(User::getEmail,null)\n                .set(User::getAge,99);\n        int update = userMapper.update(null, queryWrapper);\n        System.out.println(&quot;update = &quot; + update);\n    }\n}<\/code><\/pre>\n<h2>5\u3001\u6838\u5fc3\u6ce8\u89e3\u4f7f\u7528<\/h2>\n<h3>1\u3001\u7406\u89e3\u548c\u4ecb\u7ecd<\/h3>\n<p>1\u3001\u4ecb\u7ecd<\/p>\n<ul>\n<li>MyBatis-Plus\u662f\u4e00\u4e2a\u57fa\u4e8eMyBatis\u6846\u67b6\u7684\u589e\u5f3a\u5de5\u5177\uff0c\u63d0\u4f9b\u4e86\u4e00\u7cfb\u5217\u7b80\u5316\u548c\u589e\u5f3a\u7684\u529f\u80fd\uff0c\u7528\u4e8e\u52a0\u5feb\u5f00\u53d1\u4eba\u5458\u5728\u4f7f\u7528MyBatis\u8fdb\u884c\u6570\u636e\u5e93\u8bbf\u95ee\u65f6\u7684\u6548\u7387\u3002<\/li>\n<\/ul>\n<p>2\u3001\u7406\u89e3\u3010\u793a\u4f8b\u4ee3\u7801\u3011<\/p>\n<ul>\n<li>\n<pre><code class=\"language-java\">public interface UserMapper extends BaseMapper<User> {\n\n}<\/code><\/pre>\n<\/li>\n<\/ul>\n<p>3\u3001\u6b64\u63a5\u53e3\u5bf9\u5e94\u7684\u65b9\u6cd5\u4e3a\u4ec0\u4e48\u4f1a\u81ea\u52a8\u89e6\u53d1 user\u8868\u7684crud\u5462\uff1f<\/p>\n<ul>\n<li>\n<p>\u9ed8\u8ba4\u60c5\u51b5\u4e0b\uff0c \u6839\u636e\u6307\u5b9a\u7684&lt;\u5b9e\u4f53\u7c7b&gt;\u7684\u540d\u79f0\u5bf9\u5e94\u6570\u636e\u5e93\u8868\u540d\uff0c\u5c5e\u6027\u540d\u5bf9\u5e94\u6570\u636e\u5e93\u7684\u5217\u540d\uff01<\/p>\n<\/li>\n<li>\n<p>\u4f46\u662f\u4e0d\u662f\u6240\u6709\u6570\u636e\u5e93\u7684\u4fe1\u606f\u548c\u5b9e\u4f53\u7c7b\u90fd\u5b8c\u5168\u6620\u5c04\uff01<\/p>\n<\/li>\n<li>\n<p>\u4f8b\u5982\uff1a \u8868\u540d t_user  \u2192 \u5b9e\u4f53\u7c7b User \u8fd9\u65f6\u5019\u5c31\u4e0d\u5bf9\u5e94\u4e86\uff01<\/p>\n<\/li>\n<\/ul>\n<p>4\u3001<strong>\u81ea\u5b9a\u4e49\u6620\u5c04\u5173\u7cfb\u5c31\u53ef\u4ee5\u4f7f\u7528mybatis-plus\u63d0\u4f9b\u7684\u6ce8\u89e3\u5373\u53ef\uff01<\/strong><\/p>\n<h3>2\u3001@TableName\u6ce8\u89e3<\/h3>\n<h4>1\u3001\u4f5c\u7528<\/h4>\n<p>1\u3001\u8868\u540d\u6ce8\u89e3\uff0c\u6807\u8bc6\u5b9e\u4f53\u7c7b\u5bf9\u5e94\u7684\u8868<\/p>\n<p>2\u3001\u5c31\u662f\u4e3a\u4e86\u8ba9\u5b9e\u4f53\u7c7b\u7684\u7c7b\u540d\uff0c\u548c\u6570\u636e\u5e93\u8868\u540d\u5bf9\u5e94\u4e0a<\/p>\n<p>3\u3001\u4f7f\u7528\u4f4d\u7f6e\uff1a\u5b9e\u4f53\u7c7b<\/p>\n<p>4\u3001\u4f8b\u5b50<\/p>\n<pre><code class=\"language-java\">@TableName(&quot;user&quot;)\n@Data\npublic class User {\n    xxxxx\n}<\/code><\/pre>\n<p>5\u3001<strong>\u5982\u679c\u5b9e\u4f53\u7c7b\u548c\u8868\u540d\u662f\u4e00\u6837\u7684\uff08\u5ffd\u7565\u5927\u5c0f\u5199\uff09\u662f\u53ef\u4ee5\u7701\u7565\u7684<\/strong><\/p>\n<p>6\u3001\u4f7f\u7528\u5168\u5c40\u8bbe\u7f6e\u524d\u7f00\u7684\u65b9\u5f0f\u8fdb\u884c\u5904\u7406<\/p>\n<ul>\n<li>\n<p>\u5c31\u662f\u5728application.yaml\u6587\u4ef6\u4e2d\u8bbe\u7f6e<\/p>\n<\/li>\n<li>\n<p>\u8bbe\u7f6e\u5982\u4e0b\uff1a<\/p>\n<\/li>\n<li>\n<pre><code class=\"language-yaml\">mybatis-plus:\nconfiguration:\n  log-impl: org.apache.ibatis.logging.stdout.StdOutImpl\ntype-aliases-package: com.atguigu.pojo\nglobal-config:\n  db-config:\n    table-prefix: t_  #\u6570\u636e\u5e93\u8868\u540d\u7684\u524d\u7f00 \u4e0d\u7528\u5728\u6bcf\u4e2a\u5b9e\u4f53\u7c7b\u914d\u7f6e\n    id-type: assign_id #\u8fd9\u4e2a\u662f\u8bbe\u7f6e\u6bcf\u4e2a\u8868\u90fd\u8fd9\u6837\uff0c\u5168\u5c40\u8bbe\u7f6e<\/code><\/pre>\n<\/li>\n<\/ul>\n<h3>3\u3001@TableId\u6ce8\u89e3<\/h3>\n<h4>1\u3001\u4f5c\u7528<\/h4>\n<p>1\u3001\u7ed9\u6570\u636e\u5e93\u8bbe\u7f6e\u4e3b\u952e\u7684\u6ce8\u89e3<\/p>\n<p>2\u3001\u4f7f\u7528\u4f4d\u7f6e\uff1a\u5b9e\u4f53\u5217\u4e3b\u952e\u5b57\u6bb5<\/p>\n<h4>2\u3001\u5b9e\u73b0<\/h4>\n<h5>1\u3001\u5355\u4e2a\u8868\u4fee\u6539\u7ec4\u4ef6<\/h5>\n<p>1\u3001\u5185\u5bb9\u5c5e\u6027<\/p>\n<table>\n<thead>\n<tr>\n<th>\u5c5e\u6027<\/th>\n<th>\u7c7b\u578b<\/th>\n<th>\u5fc5\u987b\u6307\u5b9a<\/th>\n<th>\u9ed8\u8ba4\u503c<\/th>\n<th>\u63cf\u8ff0<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>value<\/td>\n<td>String<\/td>\n<td>\u5426<\/td>\n<td>&quot;&quot;<\/td>\n<td>\u4e3b\u952e\u5b57\u6bb5\u540d<\/td>\n<\/tr>\n<tr>\n<td>type<\/td>\n<td>Enum<\/td>\n<td>\u5426<\/td>\n<td>IdType.NONE<\/td>\n<td>\u6307\u5b9a\u4e3b\u952e\u7c7b\u578b<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>2\u3001IDType\u5c5e\u6027\u53ef\u9009\u503c<\/p>\n<table>\n<thead>\n<tr>\n<th>\u503c<\/th>\n<th>\u63cf\u8ff0<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>AUTO<\/td>\n<td>\u6570\u636e\u5e93 ID \u81ea\u589e (mysql\u914d\u7f6e\u4e3b\u952e\u81ea\u589e\u957f)<\/td>\n<\/tr>\n<tr>\n<td>ASSIGN_ID\uff08\u9ed8\u8ba4\uff09<\/td>\n<td>\u5206\u914d ID(\u4e3b\u952e\u7c7b\u578b\u4e3a Number(Long )\u6216 String)(since 3.3.0),\u4f7f\u7528\u63a5\u53e3<code>IdentifierGenerator<\/code>\u7684\u65b9\u6cd5<code>nextId<\/code>(\u9ed8\u8ba4\u5b9e\u73b0\u7c7b\u4e3a<code>DefaultIdentifierGenerator<\/code>\u96ea\u82b1\u7b97\u6cd5)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>3\u3001\u4f8b\u5b50<\/p>\n<pre><code class=\"language-java\">\/\/    \u4ece\u5355\u4e00\u8868\u8bbe\u7f6e\uff0c\u6570\u636e\u4e3b\u952e\u81ea\u589e\u957f\n    @TableId(type = IdType.AUTO )\n    private Integer id;<\/code><\/pre>\n<h5>2\u3001\u5168\u5c40\u914d\u7f6e\u4fee\u6539\u4e3b\u952e<\/h5>\n<p>1\u3001\u5b9e\u73b0<\/p>\n<pre><code class=\"language-yaml\">mybatis-plus:\n  configuration:\n    # \u914d\u7f6eMyBatis\u65e5\u5fd7\n    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl\n  global-config:\n    db-config:\n      # \u914d\u7f6eMyBatis-Plus\u64cd\u4f5c\u8868\u7684\u9ed8\u8ba4\u524d\u7f00\n      table-prefix: t_\n      # \u914d\u7f6eMyBatis-Plus\u7684\u4e3b\u952e\u7b56\u7565\n      id-type: auto<\/code><\/pre>\n<h4>3\u3001\u4ec0\u4e48\u65f6\u5019\u7528\uff1f<\/h4>\n<p>1\u3001\u5b9e\u4f53\u7c7b\u7684\u5b57\u6bb5\u4e0e\u6570\u636e\u5e93\u8868\u7684\u4e3b\u952e\u5b57\u6bb5\u4e0d\u540c\u540d\uff1a<\/p>\n<ul>\n<li>\u5982\u679c\u5b9e\u4f53\u7c7b\u4e2d\u7684\u5b57\u6bb5\u4e0e\u6570\u636e\u5e93\u8868\u7684\u4e3b\u952e\u5b57\u6bb5\u4e0d\u4e00\u81f4\uff0c\u9700\u8981\u4f7f\u7528<code>@TableId<\/code>\u6ce8\u89e3\u6765\u6307\u5b9a\u5b9e\u4f53\u7c7b\u4e2d\u8868\u793a\u4e3b\u952e\u7684\u5b57\u6bb5\u3002<\/li>\n<\/ul>\n<p>2\u3001\u4e3b\u952e\u751f\u6210\u7b56\u7565\u4e0d\u662f\u9ed8\u8ba4\u7b56\u7565\uff1a<\/p>\n<ul>\n<li>\u5982\u679c\u9700\u8981\u4f7f\u7528\u9664\u4e86\u9ed8\u8ba4\u4e3b\u952e\u751f\u6210\u7b56\u7565\u4ee5\u5916\u7684\u7b56\u7565\uff0c\u4e5f\u9700\u8981\u6dfb\u52a0<code>@TableId<\/code>\u6ce8\u89e3\uff0c\u5e76\u901a\u8fc7<code>value<\/code>\u5c5e\u6027\u6307\u5b9a\u751f\u6210\u7b56\u7565\u3002<\/li>\n<\/ul>\n<h4>4\u3001\u96ea\u82b1\u7b97\u6cd5<\/h4>\n<h5>1\u3001\u4f7f\u7528\u573a\u666f<\/h5>\n<p>1\u3001\u96ea\u82b1\u7b97\u6cd5\uff08Snowflake Algorithm\uff09\u662f\u4e00\u79cd\u7528\u4e8e\u751f\u6210\u552f\u4e00ID\u7684\u7b97\u6cd5\u3002\u5b83\u7531Twitter\u516c\u53f8\u63d0\u51fa\uff0c\u7528\u4e8e\u89e3\u51b3\u5206\u5e03\u5f0f\u7cfb\u7edf\u4e2d\u751f\u6210\u5168\u5c40\u552f\u4e00ID\u7684\u9700\u6c42\u3002<\/p>\n<p>2\u3001\u5728\u4f20\u7edf\u7684\u81ea\u589eID\u751f\u6210\u65b9\u5f0f\u4e2d\uff0c\u4f7f\u7528\u5355\u70b9\u6570\u636e\u5e93\u751f\u6210ID\u4f1a\u6210\u4e3a\u7cfb\u7edf\u7684\u74f6\u9888\uff0c\u800c\u96ea\u82b1\u7b97\u6cd5\u901a\u8fc7\u5728\u5206\u5e03\u5f0f\u7cfb\u7edf\u4e2d\u751f\u6210\u552f\u4e00ID\uff0c\u907f\u514d\u4e86\u5355\u70b9\u6545\u969c\u548c\u6027\u80fd\u74f6\u9888\u7684\u95ee\u9898\u3002<\/p>\n<h5>2\u3001\u7ec4\u6210\u90e8\u5206<\/h5>\n<p>1\u3001\u662f\u4e00\u4e2a64\u4f4d\u7684\u6574\u6570<\/p>\n<p>2\u3001\u65f6\u95f4\u6233\uff1a41\u4f4d\uff0c\u7cbe\u786e\u5230\u6beb\u79d2\u7ea7\uff0c\u53ef\u4ee5\u4f7f\u752869\u5e74\u3002<\/p>\n<p>3\u3001\u8282\u70b9ID\uff1a10\u4f4d\uff0c\u7528\u4e8e\u6807\u8bc6\u5206\u5e03\u5f0f\u7cfb\u7edf\u4e2d\u7684\u4e0d\u540c\u8282\u70b9\u3002<\/p>\n<p>4\u3001\u5e8f\u5217\u53f7\uff1a12\u4f4d\uff0c\u8868\u793a\u5728\u540c\u4e00\u6beb\u79d2\u5185\u751f\u6210\u7684\u4e0d\u540cID\u7684\u5e8f\u53f7\u3002<\/p>\n<h5>3\u3001\u5de5\u4f5c\u65b9\u5f0f<\/h5>\n<ol>\n<li>\u5f53\u524d\u65f6\u95f4\u6233\u4ece\u67d0\u4e00\u56fa\u5b9a\u7684\u8d77\u59cb\u65f6\u95f4\u5f00\u59cb\u8ba1\u7b97\uff0c\u53ef\u4ee5\u7528\u4e8e\u8ba1\u7b97ID\u7684\u65f6\u95f4\u90e8\u5206\u3002<\/li>\n<li>\u8282\u70b9ID\u662f\u5206\u5e03\u5f0f\u7cfb\u7edf\u4e2d\u6bcf\u4e2a\u8282\u70b9\u7684\u552f\u4e00\u6807\u8bc6\uff0c\u53ef\u4ee5\u901a\u8fc7\u914d\u7f6e\u6216\u81ea\u52a8\u5206\u914d\u7684\u65b9\u5f0f\u83b7\u5f97\u3002<\/li>\n<li>\u5e8f\u5217\u53f7\u7528\u4e8e\u8bb0\u5f55\u5728\u540c\u4e00\u6beb\u79d2\u5185\u751f\u6210\u7684\u4e0d\u540cID\u7684\u5e8f\u53f7\uff0c\u4ece0\u5f00\u59cb\u81ea\u589e\uff0c\u6700\u591a\u652f\u63014096\u4e2aID\u751f\u6210\u3002<\/li>\n<\/ol>\n<h5>4\u3001\u6ce8\u610f<\/h5>\n<p>1\u3001\u96ea\u82b1\u7b97\u6cd5\u662f\u4e00\u79cd\u7b80\u5355\u4f46\u6709\u6548\u7684\u751f\u6210\u552f\u4e00ID\u7684\u7b97\u6cd5\uff0c\u5e7f\u6cdb\u5e94\u7528\u4e8e\u5206\u5e03\u5f0f\u7cfb\u7edf\u4e2d<\/p>\n<p>2\u3001\u5982\u5fae\u670d\u52a1\u67b6\u6784\u3001\u5206\u5e03\u5f0f\u6570\u636e\u5e93\u3001\u5206\u5e03\u5f0f\u9501\u7b49\u573a\u666f\uff0c\u4ee5\u6ee1\u8db3\u5168\u5c40\u552f\u4e00\u6807\u8bc6\u7684\u9700\u6c42\u3002<\/p>\n<p>3\u3001\u91cd\u70b9\uff0c\u9700\u8981\u8bb0\u4f4f\uff1a<strong>\u96ea\u82b1\u7b97\u6cd5\u751f\u6210\u7684\u6570\u5b57,\u9700\u8981\u4f7f\u7528Long \u6216\u8005 String\u7c7b\u578b\u4e3b\u952e!!<\/strong><\/p>\n<h3>4\u3001@TableField\u6ce8\u89e3<\/h3>\n<h4>1\u3001\u4f5c\u7528<\/h4>\n<p>1\u3001\u5b57\u6bb5\u6ce8\u89e3\uff08\u975e\u4e3b\u952e\uff09<\/p>\n<p>2\u3001\u5c31\u662f\u7ed9\u5b9e\u4f53\u7c7b\u7684\u5b57\u6bb5\u8fdb\u884c\u6ce8\u89e3\uff0c\u6015\u6570\u636e\u5e93\u548c\u5b9e\u4f53\u7c7b\u7684\u540d\u5b57\u4e0d\u4e00\u6837<\/p>\n<h4>2\u3001\u5c5e\u6027<\/h4>\n<table>\n<thead>\n<tr>\n<th>\u5c5e\u6027<\/th>\n<th>\u7c7b\u578b<\/th>\n<th>\u5fc5\u5b9a\u5236\u5b9a<\/th>\n<th>\u9ed8\u8ba4\u503c<\/th>\n<th>\u63cf\u8ff0<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>value<\/td>\n<td>String<\/td>\n<td>\u5426<\/td>\n<td>&quot;&quot;<\/td>\n<td>\u6570\u636e\u5e93\u5b57\u6bb5\u540d\u79f0<\/td>\n<\/tr>\n<tr>\n<td>exist<\/td>\n<td>boolean<\/td>\n<td>\u5426<\/td>\n<td>true<\/td>\n<td>\u662f\u5426\u4e3a\u6570\u636e\u5e93\u7684\u5b57\u6bb5<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h4>3\u3001\u6ce8\u610f<\/h4>\n<p>1\u3001<strong>MyBatis-Plus\u4f1a\u81ea\u52a8\u5f00\u542f\u9a7c\u5cf0\u547d\u540d\u98ce\u683c\u6620\u5c04!!!<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e8c\u3001Mybatis-Plus\u6838\u5fc3\u529f\u80fd 1\u3001\u57fa\u4e8eMapper\u63a5\u53e3\u7684CRUD 1\u3001\u901a\u7528 CRUD \u5c01\u88c5BaseMa [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[13],"tags":[],"class_list":["post-5816","post","type-post","status-publish","format-standard","hentry","category-mybatisplus"],"_links":{"self":[{"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/posts\/5816","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/comments?post=5816"}],"version-history":[{"count":1,"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/posts\/5816\/revisions"}],"predecessor-version":[{"id":5817,"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/posts\/5816\/revisions\/5817"}],"wp:attachment":[{"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/media?parent=5816"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/categories?post=5816"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/tags?post=5816"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}