TSQL - HAVING子句中的聚合

Question

我知道这个问题已经被问了很多但是当我解决错误消息并使用HAVING子句时,我仍然收到了可怕的:

An aggregate may not appear in the WHERE clause unless it is in a 
subquery contained in a HAVING clause or a select list, 
and the column being aggregated is an outer reference.

我做错了什么,在这里？

SELECT
mr.ClubKeyNumber,
COUNT(mr.MonthlyReportID),
SUM(CONVERT(int,mr.Submitted))
FROM MonthlyReport mr
WHERE mr.ReportYear = 2014
AND COUNT(mr.MonthlyReportID) = 12
GROUP BY mr.ClubKeyNumber
HAVING (SUM(CONVERT(int,mr.Submitted))) > 11

Answer 1

问题不HAVING在于您的WHERE条款中的条款.

你count的where子句中有一个聚合,试试这个:

SELECT
mr.ClubKeyNumber,
COUNT(mr.MonthlyReportID),
SUM(CONVERT(int,mr.Submitted))
FROM MonthlyReport mr
WHERE mr.ReportYear = 2014
GROUP BY mr.ClubKeyNumber
HAVING (SUM(CONVERT(int,mr.Submitted))) > 11 and COUNT(mr.MonthlyReportID) = 12

该where子句检查在group by子句之前聚合的每一行.它不能count你MonthlyReportID,直到之后的group by所以它移动到having clause.

这是一个简单的例子,您可以使用它来演示vs的位置.