[Java] springboot整合mybatis-plus实现多表分页查询的示例代码

<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.1.1</version>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.0.1</version>
</dependency>

server:
port: 8080
spring:
datasource:
url: jdbc:mysql://localhost:3306/mybatisplus?useUnicode=true&characterEncoding=utf-8&zeroDateTimeBehavior=convertToNull&useSSL=false&serverTimezone=UTC
username: root
password: 数据库密码
mybatis:
mapper-locations: classpath*:mapper/*.xml
 
mybatis-plus:
mapper-locations: classpath:/mapper/*Mapper.xml
logging:
level:
com.tuanzi.*: debug

省略import
@EnableTransactionManagement
@Configuration
@MapperScan("com.tuanzi.*.mapper*")
public class MybatisPlusConfig {
 
/**
* 分页插件
*/
@Bean
public PaginationInterceptor paginationInterceptor(){
return new PaginationInterceptor();
}
}

@RestController
@RequestMapping("/user")
public class UserController {
 
@Autowired
UserService userService;
 
/**
* 多表关联，分页查询(1对1)
* @param page
* @return
*/
@RequestMapping("/findAll")
public Result<IPage<User>> findAll(@RequestBody Page<User> page){
 
return userService.pages(page);
 
}
 
/**
* 多表关联，分页查询(1对多)
* @param page
* @return
*/
@RequestMapping("/selectAll")
public Result<IPage<User>> selectAll(@RequestBody Page<User> page){
 
return userService.pageList(page);
 
}
}

public interface UserService extends IService<User> {
 
Result<IPage<User>> pages(Page<User> page);
 
Result<IPage<User>> pageList(Page<User> page);
}

@Service
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService {
 
@Autowired
UserMapper userMapper;
@Override
public Result<IPage<User>> pages(Page<User> page) {
IPage<User> userIPage = userMapper.Pages(page);
return Result.getSuccess("分页查询成功",userIPage);
}
 
@Override
public Result<IPage<User>> pageList(Page<User> page) {
IPage<User> userIPage = userMapper.pageList(page);
return Result.getSuccess("分页查询成功",userIPage);
}
}

@Mapper
@Repository
public interface UserMapper extends BaseMapper<User> {
 
IPage<User> Pages(@Param("page") Page<User> page);
 
IPage<User> pageList(@Param("page") Page<User> page);
}

<!-- 一对一 通用查询映射结果 -->
<resultMap id="BaseResultMap1" type="com.tuanzi.user.entity.User">
<result column="id" property="id" />
<result column="name" property="name" />
<result column="age" property="age" />
<result column="email" property="email" />
<!--assocication 一对一关联查询
可以指定联合的JavaBean对象
property="work"指定哪个属性是联合的对象
javaType:指定这个属性对象的类型
-->
<association property="work" javaType="com.tuanzi.user.entity.Work">
<result column="id" property="id" />
<result column="position" property="position" />
<result column="user_id" property="userId" />
</association>
</resultMap>

<!-- 一对多 通用查询映射结果 -->
<resultMap id="BaseResultMap2" type="com.tuanzi.user.entity.User">
<result column="id" property="id" />
<result column="name" property="name" />
<result column="age" property="age" />
<result column="email" property="email" />
<!--
collection定义关联结合类型的属性的封装规则
property="workList"指定哪个属性是联合的对象
ofType：指定集合里面元素的类型
-->
<collection property="workList" ofType="com.tuanzi.user.entity.Work">
<result column="id" property="id" />
<result column="position" property="position" />
<result column="user_id" property="userId" />
</collection>
</resultMap>

<select id="Pages" resultMap="BaseResultMap1">
select a.id id,a.name name,a.age age,a.email email,b.position position,b.user_id user_id from user a LEFT JOIN work b on a.id=b.user_id
</select>
<select id="pageList" resultMap="BaseResultMap2">
select a.id id,a.name name,a.age age,a.email email,b.position position,b.user_id user_id from user a LEFT JOIN work b on a.id=b.user_id
</select>