常用SQL语句

--主键 ALTER TABLE [GBTerminal].[TerminalDec] DROP CONSTRAINT [PK__Terminal__C451DB3124C84789]; ALTER TABLE [GBTerminal].[TerminalDec] ADD CONSTRAINT [PK_TerminalDec] PRIMARY KEY CLUSTERED ( [Tid] ASC ) GO --建唯一索引 注意sp_helpconstraint不会显示索引，要用sp_helpindex DROP INDEX [IX_TerminalDec_useid] ON [GBTerminal].[TerminalDec] CREATE UNIQUE NONCLUSTERED INDEX [IX_TerminalDec_useid] ON [GBTerminal].[TerminalDec] ( [AreaCode] ASC, [useid] ASC ) drop index IX_user on meter CREATE UNIQUE NONCLUSTERED INDEX IX_F10_1 ON GBTerminal.F10 (tid,txdz) --外键 ALTER TABLE GBTerminal.F27 WITH CHECK ADD CONSTRAINT [FK_F10] FOREIGN KEY(tid,cldh) REFERENCES GBTerminal.f10(tid,cldh) ON UPDATE CASCADE ON DELETE no action --check检查 alter table GBTerminal.F11 add constraint CK_mcsx check(mcsx<4) --默认值 ALTER TABLE GBTerminal.F10 ADD CONSTRAINT DF_F10_txmm DEFAULT ('1') FOR txmm --更改架构 alter schema GBTerminal transfer dbo.f27 --链接服务器 EXEC master.dbo.sp_addlinkedserver @server = N'58.18.173.3', @srvproduct=N'SQL Server' /* For security reasons the linked server remote logins password is changed with ######## */ EXEC master.dbo.sp_addlinkedsrvlogin @rmtsrvname=N'58.18.173.3',@useself=N'False',@locallogin=NULL,@rmtuser=N'sa',@rmtpassword='########' --select * from [58.18.173.3].ch51.dbo.meter where rtu_id=11 go --更改sa密码（已知sa现密码）用sa登录，旧密码写null。可以更改任何用户的密码。 exec sp_password Null,'newpassword,'sa' go --给视图加扩展属性 EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'电表视图' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'VIEW',@level1name=N'vw_meter' go --给表字段加扩展属性 EXEC sys.sp_addextendedproperty @level0type=N'SCHEMA', @level0name=N'GBTerminal', @level1type=N'TABLE',@level1name=N'f10', @level2type=N'COLUMN',@level2name=N'Stamp', @name=N'MS_Description',@value=N'总分表类型'; --case语句 declare @x numeric(6,2); declare @y numeric(6,2); set @x=35; set @y=case when @x=0 then 0 else 20/@x end; select @y as result; --用exists做判断 if exists(select m_id from meter where M_Id=22222) select 'yes' else select 'no' --修改列 alter table daylinelose alter column tran_id int not null alter table daylinelose alter column powerdate smalldatetime not null --查看一个数据表的触发器 sp_depends 'DelMeterTrigger' sp_helptrigger 'meter' --查看数据中所有的触发器 select * from sys.objects where type='tr' --分组与having select rtu_id,COUNT(*) from meter where rtu_id>9000 group by rtu_id having COUNT(*)>900