MyBatisPlus-QueryWrapper多条件查询及修改方式

@Test
public void queryWrapperOne() {
    QueryWrapper<User> queryWrapper = new QueryWrapper<>();
    queryWrapper.
            isNull("name")
            .ge("age", 23)
            .isNotNull("email");
    // 逻辑删除
    int result = userMapper.delete(queryWrapper);
    System.out.println(result);
    // 最终的语句为：UPDATE user SET deleted=1 WHERE deleted=0 AND name IS NULL AND age >= ? AND email IS NOT NULL
}

@Test
public void queryWrapperTwo() {
    QueryWrapper<User> queryWrapper = new QueryWrapper<>();
    queryWrapper.eq("name", "BNTang");
    // selectOne：返回的是一条记录，当出现多条时会报错
    User user = userMapper.selectOne(queryWrapper);
    System.out.println(user);
}

@Test
public void queryWrapperFour() {
    QueryWrapper<User> queryWrapper = new QueryWrapper<>();
    Map<String, Object> queryParamsMap = new HashMap<>();
    queryParamsMap.put("id", 1373266771933462530L);
    queryParamsMap.put("name", "BNTang");
    queryParamsMap.put("age", 23);
    queryWrapper.allEq(queryParamsMap);
    List<User> users = userMapper.selectList(queryWrapper);
    users.forEach(System.out::println);
}

@Test
public void queryWrapperFive() {
    QueryWrapper<User> queryWrapper = new QueryWrapper<>();
    queryWrapper
            .notLike("name", "BNTang")
            .likeRight("email", "zq");
    // 返回值是Map列表
    List<Map<String, Object>> users = userMapper.selectMaps(queryWrapper);
    users.forEach(System.out::println);
}

@Test
public void queryWrapperSix() {
   QueryWrapper<User> queryWrapper = new QueryWrapper<>();
    queryWrapper.in("id", 1, 2, 3);
    queryWrapper.inSql("id", "select id from user where id < 3");
    // 返回值是Object列表
    List<Object> users = userMapper.selectObjs(queryWrapper);
    users.forEach(System.out::println);
}

@Test
public void queryWrapperSeven() {
    // 修改值
    User user = new User();
    user.setAge(99);
    user.setName("BNTang6666");
    // 修改条件
    UpdateWrapper<User> userUpdateWrapper = new UpdateWrapper<>();
    userUpdateWrapper
            .like("name", "BNTang")
            .or()
            .between("age", 20, 30);
    int result = userMapper.update(user, userUpdateWrapper);
    System.out.println(result);
}

@Test
public void queryWrapperEight() {
    // 修改值
    User user = new User();
    user.setAge(99);
    user.setName("BNTang6666");
    // 修改条件
    UpdateWrapper<User> userUpdateWrapper = new UpdateWrapper<>();
    userUpdateWrapper
            .like("name", "A")
            .or(i -> i.eq("name", "BNTang6666").ne("age", 20));
    int result = userMapper.update(user, userUpdateWrapper);
    System.out.println(result);
}

@Test
public void queryWrapperNine() {
    QueryWrapper<User> queryWrapper = new QueryWrapper<>();
    queryWrapper.orderByDesc("id");
    List<User> users = userMapper.selectList(queryWrapper);
    users.forEach(System.out::println);
}

@Test
public void queryWrapperTen() {
    QueryWrapper<User> queryWrapper = new QueryWrapper<>();
    queryWrapper.last("limit 1");
    List<User> users = userMapper.selectList(queryWrapper);
    users.forEach(System.out::println);
}

@Test
public void queryWrapperEleven() {
    QueryWrapper<User> queryWrapper = new QueryWrapper<>();
    queryWrapper.select("id", "name", "age");
    
    List<User> users = userMapper.selectList(queryWrapper);
    users.forEach(System.out::println);
}

@Test
public void queryWrapperTwelve() {
    // 修改值
    User user = new User();
    user.setAge(10);
    // 修改条件
    UpdateWrapper<User> userUpdateWrapper = new UpdateWrapper<>();
    userUpdateWrapper
            .like("name", "A")
            // 除了可以查询还可以使用set设置修改的字段
            .set("name", "BNTang")
            // 可以有子查询
            .setSql(" email = '303158131@qq.com'");
    int result = userMapper.update(user, userUpdateWrapper);
    System.out.println(result);
}