mybatis-plus分页查询的实现示例

按照官方文档进行的配置：快速开始|mybatis-plus

引入依赖：

  　　
   com.baomidou
   mybatis-plus-boot-starter
   3.2.0
  
  
  
   mysql
   mysql-connector-java
   5.1.27
  
  
  
   com.alibaba
   druid
   1.0.29
　　　　

在application.yml配置

spring:
 datasource:
 type: com.alibaba.druid.pool.DruidDataSource
 driver-class-name: com.mysql.jdbc.Driver
 url: jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=UTF-8
 username: root
 password: 123456

在启动类上面添加@MapperScan注解，扫描mapper包

@SpringBootApplication
@MapperScan("com.qiao.demo02.mapper")
public class SpringbootDemo02Application {

 public static void main(String[] args) {
  SpringApplication.run(SpringbootDemo02Application.class, args);
 }

}

新建User和UserMapper

user类

@Data
public class User {
 @TableId
 private Integer userId;
 private String userName;
 private Integer userAge;
 private String userEmail;
}

UserMapper接口

 public interface UserMapper extends BaseMapper {
 
 }

最重要的是继承BaseMapper接口：里面声明了很强大的CRUD方法

public interface BaseMapper extends Mapper {
 int insert(T entity);

 int deleteById(Serializable id);

 int deleteByMap(@Param("cm") Map columnMap);

 int delete(@Param("ew") Wrapper wrapper);

 int deleteBatchIds(@Param("coll") Collection idList);

 int updateById(@Param("et") T entity);

 int update(@Param("et") T entity, @Param("ew") Wrapper updateWrapper);

 T selectById(Serializable id);

 List selectBatchIds(@Param("coll") Collection idList);

 List selectByMap(@Param("cm") Map columnMap);

 T selectOne(@Param("ew") Wrapper queryWrapper);

 Integer selectCount(@Param("ew") Wrapper queryWrapper);

 List selectList(@Param("ew") Wrapper queryWrapper);

 List> selectMaps(@Param("ew") Wrapper queryWrapper);

 List