@H_404_0@ 表/连接/一张表和另一张表的聚合字段连接
@H_404_0@
@H_404_0@用Northwind中的表:
@H_404_0@
SELECT CustomersID,CompanyName,ContactName,Address,
City,Region,Phone,a.orderCount
FROM dbo.CustomersInfo,(SELECT CustomerID,SUM(OrderAmount) AS orderCount FROM dbo.Orders GROUP BY CustomerID) as a
WHERE CustomersInfo.CustomersID=a.CustomerID
@H_404_0@主要把select的结果集重新命名a
@H_404_0@这样就可以调用a的字段了