SQL Group By in Update

Question

我需要使用我的quotemodifiers表中ComContribPct的總和更新我的報價表中的ComContribPct。我的報價表中列出的每個報價基本上都會有一筆數額。怎麼做 ？現在sql在我的查詢的最後一行抱怨我的Group By。賈森 -

UPDATE q 
SET q.ComContribPct= SUM(ISNULL(qm.ComContribPct,0)) 
FROM Quote q INNER JOIN QuoteModifiers qm ON q.QuoteNum=qm.QuoteNum 
GROUP BY qm.QuoteNum 

SQL給我

消息156，級別15，狀態1，行17 附近關鍵字 '集團'

Answer 1

您查詢等效於語法不正確這個（並且你沒有在更新底部出現的問題）

UPDATE q 
set q.ComContribPct = t.my_sum 
from Quote q inner join (
    select QuoteNum, SUM(ISNULL(ComContribPct,0)) as my_sum 
    from QuoteModifiers 
    group by QuoteNum 
) t on q.QuoteNum=t.QuoteNum 

Answer 2

您可以在子查詢中執行彙總，然後加入更新：

update q 
set q.ComContribPct = qm.ComContribPct 
from Quote q 
inner join (
    select QuoteNum, 
     SUM(coalesce(ComContribPct, 0)) as ComContribPct 
    from QuoteModifiers 
    group by QuoteNum 
    ) qm on q.QuoteNum = qm.QuoteNum