SQL中group by 之后仍然有重复值,请问这是什么原因呀?
我想查出总和为0的用户id,发现如果不加distinct的话就会报错"[21000][1241] Operand should contain 1 column(s)"
但是我理解的是按照id group by 之后,id应该不会有重复呀? 请问大家这是为什么呢?
select distinct id from
(
select
id
,sum(product) 总和
from list
group by 1
having 总和 = 0
) as t1