摘要：
一个我写的实例：其中多表连接，一共连接了3个表。使用聚集函数SUM，用到了GROUP BYSELECT a.[UserID],b.[Name],sum (c.[Money]+c.[Bank])as TotalMoneyFROM Table1 a(nolock) LEFTJOIN Table2 b(nolock) on a.[UserID]= b.[UserID] LEFTJOIN Table3 c(nolock) ON b.[UserID]=c.[UserID] WHERE a.[UserID]= b.[UserID]and a.[UserID]= c.[UserID]and a.[Time] 阅读全文