简单计数Mysql查询

Question

receipt_id   order_id 
1      A 
2      B 
3      B 
4      C 
5      C 

什么是SQL代码来显示此表中的所有记录，其中order_id的计数是多于1？

Answer 1

试试这个：

Select * from table where order_id in (select distinct order_id 
from table 
group by order_id 
having count(order_id) > 1) 

DEMO

Answer 2

你只需要聚合函数与GROUP BY

select order_id 
from yourtable 
group by order_id 
having count(order_id) > 1 

见SQL Fiddle with Demo