mybatis-plus中的select

1.根据id进行查询

	/**
     * 根据id查询
     */
    @Test
    void testSelectById(){
        User user = userMapper.selectById(1L);
        System.out.println(user);
    }

2.id批量查询

	/**
     * 根据多个id查询
     */
    @Test
    void testSelectByIds(){
        List<User> users = userMapper.selectBatchIds(Arrays.asList(1, 2, 3));
        users.forEach(System.out::println);
    }

3. 简单的条件查询

	/**
     * 简单的条件查询
     */
    @Test
    void testSelectByWarper(){
        HashMap<String, Object> map = new HashMap<>();
        map.put("name", "赵六");
        map.put("age", 18);
        List<User> users = userMapper.selectByMap(map);
        users.forEach(System.out::println);
    }