一.插入操作
基于上篇文章:https://blog.csdn.net/weixin_54401017/article/details/125744429?spm=1001.2014.3001.5502
测试
@Test
public void TestInsert(){
User user = new User();
user.setName("zs");
int i = userMapper.insert(user);
}
注意:实体中
@TableId(type = IdType.AUTO):这个用来设置主键的增加方式,默认是自增长
@TableField
二.更新
1.根据id更新
2.根据条件更新
三.删除
1.根据id进行删除
@Test
public void testDeleteById(){
int i = userMapper.deleteById(1);
}
2.根据map进行删除
@Test
public void testDeleteByMap(){
Map<String,Object> map = new HashMap<>();
map.put("name","zs");
//根据map删除数据,多条件之间是AND关系
int i = userMapper.deleteByMap(map);
}
3.根据QueryWrapper进行删除
@Test
public void testDeleteByQueryWrapper(){
QueryWrapper<User> queryWrapper = new QueryWrapper<>();
queryWrapper.eq("id",1).eq("name","zs");
//根据包装条件进行删除
int i = userMapper.delete(queryWrapper);
}
4.根据UpdateWrapper进行删除
@Test
public void testDeleteByUpdateWrapper(){
User user = new User();
user.setId(1);
user.setName("zs");
UpdateWrapper<User> UpdateWrapper = new UpdateWrapper<>(user);
//根据包装条件删除
int i = userMapper.delete(UpdateWrapper);
}
5.根据ids集合进行删除
@Test
public void testDeleteByBatchIds(){
ArrayList<Integer> list = new ArrayList<>();
list.add(1);
list.add(2);
int i = userMapper.deleteBatchIds(list);
}
四.查询
1.根据id进行查询
@Test
public void testSelectById(){
User user = userMapper.selectById(1);
}
2.根据ids集合进行查询
@Test
public void testSelectByIds(){
ArrayList<Integer> list = new ArrayList<>();
list.add(1);
list.add(2);
List<User> userList = userMapper.selectBatchIds(list);
}
3.根据QueryWrapper查询一条数据
@Test
public void testSelectOne(){
QueryWrapper<User> queryWrapper = new QueryWrapper<>();
//查询条件
queryWrapper.eq("name","li");
//查询出的数据超过一条时,会抛出异常
User user = userMapper.selectOne(queryWrapper);
}
4.查询满足条件的数据条数
5. 查询满足条件的数据
6.分页查询
首先需要一个配置类中配置分页插件
import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
@Configuration
@MapperScan("com.cd.mp.mapper")
public class MybatisPlusConfig {
@Bean//设置分页插件
public PaginationInterceptor paginationInterceptor(){
return new PaginationInterceptor();
}
}