摘要:
Select字句在逻辑上是SQL语句最后进行处理的最后一步,所以,以下查询会发生错误:SELECT YEAR(OrderDate) AS OrderYear, COUNT(DISTINCT CustomerID) AS NumCustsFROM dbo.OrdersGROUP BY OrderYea... 阅读全文
摘要:
sqlserver中判断表或临时表是否存在1、判断数据表是否存在 方法一:use yourdb;goif object_id(N'tablename',N'U') is not nullprint '存在'elseprint '不存在'例如:use fireweb;goif object_id(N... 阅读全文