MYSQL 执行分组查询最大时间的数据问题

我要实现的是按一个字段分组获得创建时间最大的数据行，但是发现获取到的数据有问题

下面是我从里面选了一条数据作为例子：

 SELECT GDLS_SHANGCICHULILISHI_GDLSID_FK,
       GDLS_GONGDAN_RWGDID_FK,
       MAX(GDLS_CREATETIME),
       COUNT(1) C
  FROM cive_t_d_gongdanlishi
  WHERE GDLS_GONGDAN_RWGDID_FK = 'a002cbae6c3b4b1bb73ee48612701433';

 SELECT GDLS_SHANGCICHULILISHI_GDLSID_FK,
       GDLS_GONGDAN_RWGDID_FK,
       GDLS_CREATETIME
FROM cive_t_d_gongdanlishi
WHERE GDLS_GONGDAN_RWGDID_FK = 'a002cbae6c3b4b1bb73ee48612701433'
ORDER BY GDLS_CREATETIME DESC;

原始语句为：

 SELECT GDLS_SHANGCICHULILISHI_GDLSID_FK,
       GDLS_GONGDAN_RWGDID_FK,
       MAX(GDLS_CREATETIME),
       COUNT(1) C
  FROM cive_t_d_gongdanlishi
  GROUP BY GDLS_GONGDAN_RWGDID_FK

SQL语句思路没问题，就是好奇怎么显示能非分组字段且非聚合函数“GDLS_SHANGCICHULILISHI_GDLSID_FK”没有报错
还有如果不想显示字段值为空的记录，就在分组后加个子语句“having GDLS_GONGDAN_RWGDID_FK is not null”