获取“[错误] 1111 - 无效使用组功能的”错误

Question

目前我在做这个查询：

SELECT Date_Format(M.Signupdate,"%Y-%m") as YearMonth, 
SUM(IF(Count(H.Nr) >= 0,1,0)) , 
SUM(IF(Count(H.Nr) >= 1,1,0)) , 
SUM(IF(Count(H.Nr) >= 2,1,0)) , 
SUM(IF(Count(H.Nr) >= 3,1,0)) 
FROM people M 
INNER JOIN History H ON H.login = M.Login 
WHERE 
M.Masteraccount = "" AND 
M.logincount > 5 AND 
DATEDIFF(M.lastlogin,M.Signupdate) >= 3 AND 
DATEDIFF(H.EntryDate,M.Signupdate) <= 151 
GROUP BY YearMonth ORDER BY YearMonth ; 

不过，我不断收到“[错误] 1111 - 无效使用组功能“错误。如果我删除SUM的它工作得很好。有人请给我答案吗？

Answer 1

你不能在GROUP BY使用别名。您需要将Date_Format(M.Signupdate,"%Y-%m")放入GROUP BY才能使其正常工作。你也不能嵌套聚合函数，所以你需要使用一个子查询来获取count，然后使用sum：

select YearMonth, 
    SUM(IF(CountNR >= 0,1,0)) , 
    SUM(IF(CountNR >= 1,1,0)) , 
    SUM(IF(CountNR >= 2,1,0)) , 
    SUM(IF(CountNR >= 3,1,0)) 
from 
(
    SELECT Date_Format(M.Signupdate,"%Y-%m") as YearMonth, 
     Count(H.Nr) CountNR 
    FROM people M 
    INNER JOIN History H 
     ON H.login = M.Login 
    WHERE M.Masteraccount = "" AND 
     M.logincount > 5 AND 
     DATEDIFF(M.lastlogin,M.Signupdate) >= 3 AND 
     DATEDIFF(H.EntryDate,M.Signupdate) <= 151 
    GROUP BY Date_Format(M.Signupdate,"%Y-%m") 
) src 
GROUP BY YearMonth 
ORDER BY YearMonth;