摘要: EXIST和IN 比如在Northwind数据库中有一个查询为 SELECT c.CustomerId,CompanyName FROM Customers cWHERE EXISTS(SELECT OrderID FROM Orders o WHERE o.CustomerID=c.Custome 阅读全文
posted @ 2019-10-16 21:21 zhm0424 阅读(680) 评论(0) 推荐(0) 编辑