物理查询处理
摘要：
查询处理期间数据流use NorthwindSELECT C.CustomerID,COUNT(O.OrderID) AS NumOrdersFROM dbo.Customers as cLEFT OUTER JOIN dbo.orders as oON C.CustomerID = O.CustomerIDWHERE C.City = 'London'GROUP BY C.CustomerIDHAVING COUNT(O.OrderID) > 5ORDER BY NumOrders;1 处理where后面的过滤条件在Customers表中来自London的消费者2 然后 阅读全文
posted @ 2012-05-25 00:30 361741352 阅读(221) 评论(0) 推荐(0) 编辑
