sql常用语法

--在表中添加字段
if col_length('JX_DomesticStudy','XL') is null
begin
alter table JX_DomesticStudy add PXlevel int default 0
end
go

--创建表
if not exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[JX_PXlevel]') and OBJECTPROPERTY(id, N'IsUserTable') = 1)
begin
CREATE TABLE [dbo].[JX_PXlevel](
[ID] [int] IDENTITY(1,1) NOT NULL,
[PXJBName] [nvarchar](20) NOT NULL,
 CONSTRAINT [PK_JX_PXlevel] PRIMARY KEY CLUSTERED
(
[ID] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]--添加[dbo].[JX_PXlevel]表和JX_DomesticStudy的主外键约束
ALTER TABLE [dbo].[JX_DomesticStudy]  WITH CHECK ADD  CONSTRAINT [FK_JX_DomesticStudy_JX_PXlevel] FOREIGN KEY([PXlevel])
REFERENCES [dbo].[JX_PXlevel] ([ID])ALTER TABLE [dbo].[JX_DomesticStudy] CHECK CONSTRAINT [FK_JX_DomesticStudy_JX_PXlevel]
end
go--向表中插入数据 
if not exists (select * from JX_PXlevel where PXJBName='国外')
begin
insert into JX_PXlevel values('国外');
end
go

--向表中添加字段
if not exists(select 1 from syscolumns where name='ZS01' and id=object_id('JX_DomesticStudy'))
begin
alter table JX_DomesticStudy add ZS01 nvarchar(30)
end
go

--教务管理中添加学生综合查询模块  add by 吴翰哲
if not exists (select * from dbo.XT_Cell where CellID='XS1301' and CellName='学生综合查询' and ModuleID='XS12' )
BEGIN
INSERT INTO dbo.XT_Cell VALUES('XS1301','学生综合查询','XS12',NULL,'/XS/BZR/BZRSearchStu/BZRSearchStuView.aspx','学生综合查询.png',1,20,1)
END
GO--清空教研组成员所需要的约束删除 add by 吴翰哲
IF  EXISTS (SELECT * FROM sys.foreign_keys WHERE object_id = OBJECT_ID(N'[dbo].[FK_XZ_Employee_JX_TeachingGroup]') AND parent_object_id = OBJECT_ID(N'[dbo].[XZ_Employee]'))
begin
ALTER TABLE [dbo].[XZ_Employee] DROP CONSTRAINT [FK_XZ_Employee_JX_TeachingGroup]
end
GO--向表中添加字段
if not exists(select * from sysColumns where name='JX_AttendClassInfo' and id=object_ID('XQMC'))
begin
   alter table JX_AttendClassInfo add XQMC VARCHAR(50) null end
GO

–数据库同步更新

update yiyao.dbo.xt_querycolumn  set FIELDALIAS = b.FIELDALIAS
from yiyao.dbo.xt_querycolumn a, panto_school.dbo.xt_querycolumn b
where a.queryobject = b.queryobject and a.attributesname = b.attributesname and a.fieldname = b.fieldname
select * from panto_school.dbo.xt_querycolumn