MP的增删改查基本操作

1.MP的增加操作

@Test
    public void insert(){
        User user = new User();
        user.setName("向中");
        user.setAge(23);
        user.setEmail("[email protected]");
        user.setManagerId(1088248166370832385L);
        user.setCreateTime(LocalDateTime.now());
        //返回影响记录数
        int rows = userMapper.insert(user);
        System.out.println("影响记录数："+rows);
    }
           

2.MP的查询操作

（1）selectById 根据 ID 查询

@Test
    public void selectById(){
        User user = userMapper.selectById(1088248166370832385L);
        System.out.println(user);
    }
           

（2）selectBatchIds 查询（根据ID 批量查询）

@Test
    public void selectByIds(){
        List<Long> asList = Arrays.asList(1088250446457389058L, 1094592041087729666L, 1186555441707827201L);
        List<User> userList = userMapper.selectBatchIds(asList);
        userList.forEach(System.out::println);
    }
           

（3）selectByMap 查询（根据 columnMap 条件）

@Test
    public void selectByMap(){
        //map.put("name","王天风")
        //map.put("age",25)
        //where name = "王天风" and age=30
        Map<String,Object> columnMap = new HashMap<>();
        columnMap.put("name","王天风");
        columnMap.put("age",25);
        List<User> userList = userMapper.selectByMap(columnMap);
        userList.forEach(System.out::println);
    }
           

3.MP的更新操作

（1）updateById 根据主键id更新

@Test
    public void updateById(){
      User user = new User();
      user.setId(1088248166370832385L);
      user.setAge(30);
      user.setEmail("[email protected]");
      int rows = userMapper.updateById(user);
      System.out.println("影响记录数："+ rows);
    }
           

（2）UpdateWrapper 更新，多条属性操作

1.多条属性更新

@Test
    public void update(){
      //  User whereUser = new User();
      //  whereUser.setName("大boss");
      //  UpdateWrapper<User> updateWrapper = new UpdateWrapper<>(whereUser);
      //  updateWrapper.eq("age",41);
        UpdateWrapper<User> updateWrapper = new UpdateWrapper<>();
        updateWrapper.eq("name","大boss").eq("age",41);
        User user = new User();
        user.setAge(41);
        user.setEmail("[email protected]");
        int rows = userMapper.update(user, updateWrapper);
        System.out.println("影响记录数：" + rows);
    }
           

2.少数属性更新，加上set

@Test
    public void update2(){
        UpdateWrapper<User> updateWrapper = new UpdateWrapper<>();
        updateWrapper.eq("name","大boss").eq("age",41).set("age",42);
        int rows = userMapper.update(null, updateWrapper);
        System.out.println("影响记录数：" + rows);
    }
           

（3）LambdaUpdateWrapper 更新操作，可以防止sql注入

1.lambdaUpdateWrapper 更新

@Test
    public void updateByLambdaWrapper(){
        LambdaUpdateWrapper<User> lambdaUpdateWrapper = Wrappers.<User>lambdaUpdate();
        lambdaUpdateWrapper.eq(User::getName,"大boss").eq(User::getAge,42).set(User::getAge,43);
        int update = userMapper.update(null, lambdaUpdateWrapper);
        System.out.println(update);
    }
           

2.LambdaUpdateChainWrapper 链式更新

@Test
    public void updateByLambdaWrapperChain(){
        boolean update = new LambdaUpdateChainWrapper<User>(userMapper)
                .eq(User::getName, "大boss").eq(User::getAge, 43).set(User::getAge, 44).update();
        System.out.println(update);
    }
           

4.MP的删除操作

（1）deleteById

@Test
    public void deleteById() {
        int delete = userMapper.deleteById(1186569110046949378L);
        System.out.println(delete);
    }
           

（2）deleteByMap

@Test
    public void deleteByMap() {
        Map<String,Object> map = new HashMap<>();
        map.put("name","向前");
        map.put("age",23);
        int deleteByMap = userMapper.deleteByMap(map);
        System.out.println(deleteByMap);
    }
           

（3）deleteBatchIds

@Test
    public void deleteByBatchIds() {
        List<Long> list = Arrays.asList(1186568191955804162L, 1186561629153402882L);
        int ids = userMapper.deleteBatchIds(list);
        System.out.println(ids);
    }
           

（4）deleteByLambdaQueryWrapper

@Test
    public void deleteByWrappersLamdba(){
        LambdaQueryWrapper<User> lambdaQueryWrapper = Wrappers.<User>lambdaQuery();
        lambdaQueryWrapper.eq(User::getAge,33).eq(User::getEmail,"[email protected]");
        int delete = userMapper.delete(lambdaQueryWrapper);
        System.out.println("删除记录："+delete);
    }
           

(5)deleteByQueryWrapper

@Test
    public void deleteByWrapper2(){
        QueryWrapper<User> queryWrapper = new QueryWrapper<>();
        queryWrapper.eq("age",23).eq("name","向中");
        int delete = userMapper.delete(queryWrapper);
        System.out.println("删除记录数："+delete);
    }