if exists(select * from sysobjects where name=约束名) alter table 表名 drop constraint 约束名; go alter table 表名 add constraint 约束名 check(约束规则),constraint 约束名 check(约束规则); go 示例: -- 添加一个默认约束 use testss; go if exists(select * from sysobjects where name='check1...
CONSTRAINT `c1_nonzero` CHECK ((`c1` <> 0)), CONSTRAINT `c2_positive` CHECK ((`c2` > 0)), CONSTRAINT `t1_chk_1` CHECK ((`c1` <> `c2`)), CONSTRAINT `t1_chk_2` CHECK ((`c1` > 10)), CONSTRAINT `t1_chk_3` CHECK ((`c3` < 100)), CONSTRAINT `t1_chk_4` CHECK ((`...
--判断是否存在'MyView52'这个试图 IF EXISTS (SELECT TABLE_NAME FROM INFORMATION_SCHEMA.VIEWS WHERE TABLE_NAME = N'MyView52') PRINT '存在' else PRINT '不存在'6 判断函数是否存在-- 判断要创建的函数名是否存在if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[函数名]'...
--或者使用EXISTS,因为EXISTS是二值逻辑只有(true,flase)所以不存在未知。 SELECT Customerid FROM DBO.Customer A WHERE NOT EXISTS(SELECT custid FROM OrderS WHERE OrderS.custid=A.Customerid ); ---in查询可以返回值,因为in是true,子查询true,flase,unknown都是真值所以可以返回子查询的true SELECT Customerid...
USE <database_name>; GO SELECT OBJECT_DEFINITION (OBJECT_ID('<schema_name.object_name>')) AS ObjectDefinition; GO TOP 如何? 檢視伺服器層級觸發程式的定義嗎? SQL 複製 SELECT definition FROM sys.server_sql_modules; GO TOP 如何? 尋找指定數據表之主鍵的數據行嗎? 執行下...
在SQL Server 物件總管 中,展開 SimpleUnitTestDB 的項目節點,然後展開 [可程式性],然後展開[預存程式] 節點。 以滑鼠右鍵按一下其中一個預存程序,然後按一下 [建立單元測試] 以顯示 [建立單元測試] 對話方塊。 選取所有五個預存程序的核取方塊: Sales.uspCancelOrder、 Sales.uspFillOrder、 Sales.uspNe...
Or do something else programmatically. Checking if an index exists is a pretty frequent task. But there’s no simple function to test if an index exists in SQL Server. Here’s what I’ll show you in this post: Example code to check if an index exists using OBJECT_ID. The code is si...
打开SQL Server 配置管理器,启用tcp/ip,重启 sql server 服务,这样可以用一些工具远程连接,SqlServer服务使用两个端口:TCP-1433、UDP-1434。 开启iis服务和asp .net 访问本地ip,如下表明iis .net 环境安装成功 默认的Web路径为C:\inetpub\wwwroot 下载Sql Server 注入的源代码,这里也可以自己写。
No time limit exists because the calls can take an arbitrary amount of time. However, the point of the calls limit is to prevent too many long-running queries from a single connection and negatively affecting other connections.For example, if a connection makes 200 calls at the same time, ...
Lock escalation is triggered when lock escalation isn't disabled on the table by using the ALTER TABLE SET LOCK_ESCALATION option, and when either of the following conditions exists: A single Transact-SQL statement acquires at least 5,000 locks on a single nonpartitioned table or index. A si...