mybatis-plus-plus（mpp）

对mybatis-plus进行增强，支持多表关联查询

使用示例 demo https://github.com/nullbull/mybatis-plus-plus-demo

接入步骤

1. 将代码down到本地，使用maven install

2. 在自己的项目中添加依赖

   <dependency>
       <groupId>com.github.mybatisplus</groupId>
       <artifactId>plus</artifactId>
       <version>1.0-SNAPSHOT</version>
   </dependency>

3. 配置方式

   • SpringBoot 配置

     @Configuration
     public class MybatisPlusConfig {
     
         @Bean
         public Interceptor myInterceptor() {
             return new MyInterceptor();
         }
     
         @Bean
         public ISqlInjector multiQueryInjector() {
             return new MultiQueryInjector();
         }
     
     }

   • Spring 配置方式

     1. 在Spring初始化中修改MybatisSqlSessionFactoryBean

     2. 添加 mpp 自定义的 mybatis 拦截器

        MybatisSqlSessionFactoryBean sqlSessionFactoryBean = new MybatisSqlSessionFactoryBean();
        
        sqlSessionFactoryBean.setPlugins(new Interceptor[]{ new MyInterceptor()});

     3. 添加 mpp 自定义的 默认方法

        GlobalConfig globalConfig = GlobalConfigUtils.defaults();
        globalConfig.setSqlInjector(new MultiQueryInjector());
        sqlSessionFactoryBean.setGlobalConfig(globalConfig);

4. 将mybaits plus 的BaseMapper 替换成mpp自定义的 MultiQueryMapper

如何使用

示例一：

Query end = new Query(TestVo.class)
    .select(F.f(Meeting::getId), F.f(Room::getId), F.f(Meeting::getTopic))
    .joinOn(F.f(Meeting::getHostId), F.f(Room::getId))
    .in(F.f(Meeting::getId), 1, 2)
    .eq(F.f(Meeting::getTopic), "测试")
    .end();
List<Object> list = meetingMapper.selectMulti(end);

生成的sql

select meeting.id,room.id,meeting.topic FROM meeting join room on meeting.host_id = room.id where meeting.id in ( ?,? ) and meeting.topic=?

示例二：

List<Object> meetingList = meetingMapper.selectMulti(new Query(Meeting.class)
           			.joinOn(F.f(Meeting::getHostId), F.f(Room::getId))
                    .eq(F.f(Room::getName), "测试会议室")
                    .end());

生成的SQL

select meeting.id,meeting.meeting_id,meeting.host_id,meeting.topi,meeting.type,meeting.created_time from meeting join room on meeting.host_id = room.id and room.name=?