完整的select语句
select distinct *
from 表名
where ...
group bu ... having ... #集合分组
order bu ...
limit star,count
执行顺序为：
from 表名
where...
group by ...
select distinct *
having...
order by ...
limit star,count
来源：https://www.cnblogs.com/lishuide/p/11657751.html