mybatis-plus_2

更新

package top.mgy.mybatistest.com.mp;

import com.baomidou.mybatisplus.core.conditions.update.UpdateWrapper;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import top.mgy.mybatistest.dao.UserMapper;
import top.mgy.mybatistest.entity.User;

@SpringBootTest
public class UpdateTest {

    @Autowired
    private UserMapper userMapper;

    @Test
    public void updateById(){
        //根据id更新数据
        User user = new User();
        user.setId(1088248166370832385L);
        user.setAge(26);
        user.setEmail("123@qq.com");

        int row = userMapper.updateById(user);
        System.out.println("影响的行数："+row);

    }

    @Test
    public void updateByWrapper(){
        //根据自定义字段更新数据
        UpdateWrapper<User> userUpdateWrapper = new UpdateWrapper<>();
        //Wrapper中设置的条件 将出现在 where 后面
        userUpdateWrapper.eq("name","李艺伟").eq("age",28);

        // user 中设置的值将出现在 set中
        User user = new User();
        user.setEmail("lyq@qq.com");
        user.setAge(29);
        int row = userMapper.update(user, userUpdateWrapper);
        System.out.println("受影响的行数:"+row);


    }
    
    
    @Test
    public void updateByWrapper2(){

        /**
         * 简便方式 ，适合于修改字段较少的时候
         */

        UpdateWrapper<User> userUpdateWrapper = new UpdateWrapper<>();
        // 直接通过 set 修改
        userUpdateWrapper.eq("name","李艺伟").eq("age",29).set("age",30);

        int row = userMapper.update(null, userUpdateWrapper);
        System.out.println("受影响的行数:"+row);


    }
    
    @Test
    public void updateByWrapper3(){
        /**
         * Lambda 方式
         */
        LambdaUpdateWrapper<User> userLambdaUpdateWrapper = Wrappers.<User>lambdaUpdate();

        userLambdaUpdateWrapper.eq(User::getName,"李艺伟").eq(User::getAge,30).set(User::getAge,31);

        int row = userMapper.update(null, userLambdaUpdateWrapper);
        System.out.println("受影响的行数:"+row);
    }
    
    
    @Test
    public void updateByWrapper4(){
        /**
         *  链式调用
         */
        boolean row = new LambdaUpdateChainWrapper<User>(userMapper)
                .eq(User::getName, "李艺伟").eq(User::getAge, 31).set(User::getAge, 32).update();
        System.out.println("是否更新成功:"+row);
    }
}

删除

package top.mgy.mybatistest.com.mp;

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import top.mgy.mybatistest.dao.UserMapper;

import java.util.HashMap;
import java.util.Map;

@SpringBootTest
public class DeleteTest {

    @Autowired
    private UserMapper userMapper;

    @Test
    public void deleteByUId(){
        int row = userMapper.deleteById(1243763737180590081L);
        System.out.println("受影响的行数："+row);
    }

    @Test
    public void deleteByMap(){
        Map<String,Object> map = new HashMap<>();

        map.put("name","向北");
        map.put("age",31);
        // 删除 name=向北 and age=31的记录
        int row = userMapper.deleteByMap(map);
        System.out.println("受影响的行数："+row);
    }
    
    
    @Test
    public void deleteBatchIds(){
        //批量删除
        int row = userMapper.deleteBatchIds(Arrays.asList(1243752778902867969L, 1243755707546284033L));
        System.out.println("受影响的行数："+row);
    }
    
    
    @Test
    public void deleteWrapper(){
        //查询构造器删除
        LambdaQueryWrapper<User> lambdaQueryWrapper = new LambdaQueryWrapper<>();
        lambdaQueryWrapper.eq(User::getAge,31);
        int row = userMapper.delete(lambdaQueryWrapper);
        System.out.println("受影响的行数："+row);
    }
}