SQL表结构操作：添加字段、描述与删除

//删除表
if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[JHCRM_Report_ss]') and OBJECTPROPERTY(id, N'IsUserTable') = 1)
   drop table [JHCRM_Report_ss] 

//添加表
if not exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[Table1]') and OBJECTPROPERTY(id, N'IsUserTable') = 1)
   create table [Table1] ([col1] int,[col2] int)

//添加字段
if not exists( select * from syscolumns where syscolumns.[name]='FNewObjectEnd' and syscolumns.[id]=(select id from dbo.sysobjects  where id=object_id(N'[dbo].[jsc_financial]') and OBJECTPROPERTY(id, N'IsUserTable') = 1) )
ALTER TABLE jsc_financial ADD FNewObjectEnd int--NULL   --添加先用项目结项数
go
EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'先用项目结项数' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'jsc_financial', @level2type=N'COLUMN',@level2name=N'FNewObjectEnd'

if not exists( select * from syscolumns where syscolumns.[name]='Record_Money' and syscolumns.[id]=(select id from dbo.sysobjects  
where id=object_id(N'[dbo].[JHCRM_Resource_Record_Main]') and OBJECTPROPERTY(id, N'IsUserTable') = 1) )
ALTER TABLE JHCRM_Resource_Record_Main ADD Record_Money numeric(12, 2)--NULL   --资源费用
go
EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'资源费用' , @level0type=N'SCHEMA',@level0name=N'dbo', 
@level1type=N'TABLE',@level1name=N'JHCRM_Resource_Record_Main', @level2type=N'COLUMN',@level2name=N'Record_Money'


//删除字段
if not exists( select * from syscolumns where syscolumns.[name]=table_Name
 and syscolumns.[id]=(select id from dbo.sysobjects  where id=object_id(N'[dbo].[tableName]')"
 and OBJECTPROPERTY(id, N'IsUserTable') = 1) )  
ALTER   TABLE    table_Name    DROP   COLUMN    tableName