我在 MS Access 中有如下查询
SELECT tblUsers.Forename, tblUsers.Surname,
(SELECT COUNT(ID)
FROM tblGrades
WHERE UserID = tblUsers.UserID
AND (Grade = 'A' OR Grade = 'B' OR Grade = 'C')) AS TotalGrades
FROM tblUsers
我已将其放入报告中,现在在尝试查看报告时显示警告“子查询中不允许使用多级 GROUP BY 子句”
我没有得到的是我什至在查询中没有任何 GROUP BY 子句,那么为什么它会返回此错误?