mysql中exists的用法介绍
摘要：
SELECT c.CustomerId, CompanyName 2 FROM Customers c 3 WHERE EXISTS( 4 SELECT OrderID FROM Orders o 5 WHERE o.CustomerID = c.CustomerID) SELECT c.Custo 阅读全文
posted @ 2016-09-20 14:41 牛奶糖13号 阅读(557) 评论(0) 推荐(0) 编辑
