問題與對包含聚合或子查詢的表達式執行聚合函數

Question

select 
    A.ACCT as acct, COUNT(TRANS_key) as payments 
from 
    DEBT A 
join 
    TRANS B on B.DEBT_KEY = A.DEBT_KEY 
join 
    TRANS_CODE C on C.TRANS_CODE = B.TRANS_CODE 
join 
    CLIENT D on D.CLIENT_KEY = A.CLIENT_KEY 
join 
    STATUS S on S.STAT_KEY = A. STAT_KEY 
where 
    S.CATEGORY = 'A' and D.CLIENT_KEY = 43 

錯誤：

Cannot perform an aggregate function on an expression containing an aggregate or a subquery.

我正在運行此當上述錯誤。我不確定我是否應該以不同的方式加入這些表格，但我需要這個工作。

Answer 1

所有其他選擇必須由group by。使用這個

select A.ACCT as acct, COUNT(TRANS_key) as payments 

from DEBT A join TRANS B on B.DEBT_KEY = A.DEBT_KEY 

join TRANS_CODE C on C.TRANS_CODE = B.TRANS_CODE 

join CLIENT D on D.CLIENT_KEY = A.CLIENT_KEY 

join STATUS S on S.STAT_KEY = A. STAT_KEY 

where S.CATEGORY = 'A' and D.CLIENT_KEY = 43 
GROUP BY A.ACCT 

Answer 2

嘗試

select A.ACCT as acct, COUNT(TRANS_key) as payments 
from DEBT A 
join TRANS B on B.DEBT_KEY = A.DEBT_KEY 
join TRANS_CODE C on C.TRANS_CODE = B.TRANS_CODE 
join CLIENT D on D.CLIENT_KEY = A.CLIENT_KEY 
join STATUS S on S.STAT_KEY = A. STAT_KEY 
where S.CATEGORY = 'A' and D.CLIENT_KEY = 43 
group by A.ACCT 

您不能使用聚合函數一樣count返回僅有1個結果和選擇返回多個。如果你想每a.acct計數，然後執行上述操作。