MySQL exists的用法介绍
摘要：
有一个查询如下：SELECT c.CustomerId, CompanyName FROM Customers c WHERE EXISTS( SELECT OrderID FROM Orders o WHERE o.CustomerID = cu.CustomerI... 阅读全文
posted @ 2014-05-25 21:18 Still water run deep 阅读(741) 评论(0) 推荐(0) 编辑