select 语句后缀顺序

1. select 语句后缀顺序

select id from table
join xxtable on xxtable.id=table.id
where id=1
group  by sex
having avg(id)>2
order by id 

后缀的顺序不能变，执行的时候也是按照 先 where 再分组这样的顺序。

2. 结果去重

select  distinct  *  
from table