Question

select acc.user_id
     , member.nickname
     , sum(credit) as ttl 
     , member.balance
  from account_history as acc
  left 
  join member
    ON acc.user_id = member.user_id
 where balance > 0 
   and balance <50
 group 
    by user_id

我想显示ttl ( sum(credit) ) > 0的行，

所以我更改为

select acc.user_id,member.nickname, sum(credit) as ttl ,member.balance
from account_history as acc left join member 
ON acc.user_id=member.user_id 
where balance > 0 and balance <50 and ttl > 0
group by user_id

但是变成错误。找不到列ttl

Answer 1

使用having子句中的值应该起作用：

select acc.user_id,member.nickname, sum(credit) as ttl ,member.balance
from account_history as acc 
    left join member ON acc.user_id=member.user_id 
where balance > 0 and balance <50 
group by user_id 
having  ttl > 0

在where子句中，您不能使用别名

另请参见https://dev.mysql.com/doc/refman/8.0/en/problems-with-alias.html

Answer 2

您应使用HAVING语句按汇总字段进行过滤

SELECT 
  acc.user_id,
  member.nickname, 
  sum(credit) as ttl,
  member.balance
FROM account_history AS acc left join member ON acc.user_id = member.user_id 
WHERE balance > 0 and balance <50
GROUP BY user_id 
HAVING ttl > 0

Answer 3

我认为它会起作用，

Select acc.user_id,member.nickname, sum(credit) as ttl ,member.balance
from account_history as acc left join member 
ON acc.user_id=member.user_id 
where balance > 0 and balance <50 and sum(credit) > 0
group by user_id

或者您也可以使用Haven子句获得相同的结果。

喜欢

Select acc.user_id,member.nickname, sum(credit) as ttl ,member.balance
from account_history as acc left join member 
ON acc.user_id=member.user_id 
where balance > 0 and balance <50
group by user_id 
having sum(credit) > 0

Answer 4

使用having和acc.user_id,member.nickname，group.balance中的member.balance

SELECT 
  acc.user_id,
  member.nickname, 
  sum(credit) as ttl,
  member.balance
FROM account_history AS acc left join member ON acc.user_id = member.user_id 
WHERE balance > 0 and balance <50
GROUP BY acc.user_id, member.nickname,member.balance
HAVING ttl > 0

Answer 5

您需要使用子查询来获取ttl列，因为它是派生列

select * from
(select acc.user_id,member.nickname, sum(credit) as ttl ,member.balance
from account_history as acc left join member 
ON acc.user_id=member.user_id 
where balance > 0 and balance <50
group by user_id 
)bal
Where ttl>0

Answer 6

在where子句中使用列别名不能像提到的here那样工作。

首先形成 from 子句中所有表的乘积。
  然后评估
where 子句以消除不满足条件的行   搜索条件。

接下来，使用 group by 子句中的列对行进行分组。

然后，具有不满足search_condition的组   。

接下来， select 子句目标列表中的表达式为   已评估。

如果select子句中存在 distinct 关键字，请复制行   现在被淘汰了。

对每个子选择进行评估后，将获取联合。

最后，结果行将根据列进行排序   在 order by 子句中指定。

where子句在select之前进行求值，因此尚不知道ttl是什么。

请参阅：Referring to a Column Alias in a WHERE Clause。

SQL在查询子句中使用总和结果

6 个答案: