SQL Group By in Update

Question

我需要使用我的quotemodifiers表中ComContribPct的总和更新我的报价表中的ComContribPct。我的报价表中列出的每个报价基本上都会有一笔数额。怎么做 ？现在sql在我的查询的最后一行抱怨我的Group By。贾森 -

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给我

消息156，级别15，状态1，行17 附近关键字 '集团'

Answer 1

您查询等效于语法不正确这个（并且你没有在更新底部出现的问题）

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

您可以在子查询中执行汇总，然后加入更新：

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