SQL Server判断对象是否存在

if exists (select*fromsys.databaseswherename= ’数据库名’) 
  dropdatabase[数据库名]  if exists (select*fromsys.databaseswherename= ’数据库名’)
  dropdatabase[数据库名]

if exists (select*fromsysobjectswhereid = object_id(N’[表名]’)andOBJECTPROPERTY(id, N’IsUserTable’) = 1) 
  droptable[表名]  if exists (select*fromsysobjectswhereid = object_id(N’[表名]’)andOBJECTPROPERTY(id, N’IsUserTable’) = 1)
  droptable[表名]

if exists (select*fromsysobjectswhereid = object_id(N’[存储过程名]’)andOBJECTPROPERTY(id, N’IsProcedure’) = 1) 
  dropprocedure[存储过程名]  if exists (select*fromsysobjectswhereid = object_id(N’[存储过程名]’)andOBJECTPROPERTY(id, N’IsProcedure’) = 1)
  dropprocedure[存储过程名]

if object_id(’tempdb..#临时表名’)isnotnull   
  droptable#临时表名  if object_id(’tempdb..#临时表名’)isnotnull 
  droptable#临时表名

IF EXISTS (Select*FROMsysviewsWhereobject_id = ’[dbo].[视图名]’ 
--SQL Server 2005  
IF EXISTS (Select*FROMsys.viewsWhereobject_id = ’[dbo].[视图名]’ --SQL Server 2000
IF EXISTS (Select*FROMsysviewsWhereobject_id = ’[dbo].[视图名]’
--SQL Server 2005
IF EXISTS (Select*FROMsys.viewsWhereobject_id = ’[dbo].[视图名]’

  if exists (select*fromdbo.sysobjectswhereid = object_id(N’[dbo].[函数名]’)andxtypein(N’FN’, N’IF’, N’TF’))   
  dropfunction[dbo].[函数名]   --  判断要创建的函数名是否存在 
  if exists (select*fromdbo.sysobjectswhereid = object_id(N’[dbo].[函数名]’)andxtypein(N’FN’, N’IF’, N’TF’)) 
  dropfunction[dbo].[函数名] 

if exists(select*fromsyscolumnswhereid=object_id(’表名’)andname=’列名’) 
  altertable表名dropcolumn列名  if exists(select*fromsyscolumnswhereid=object_id(’表名’)andname=’列名’)
  altertable表名dropcolumn列名

if columnproperty(object_id(’table’),’col’,’IsIdentity’)=1 
  print ’自增列’ 
else 
  print ’不是自增列’ 
   
Select*FROMsys.columnsWhereobject_id=OBJECT_ID(’表名’) 
ANDis_identity=1  if columnproperty(object_id(’table’),’col’,’IsIdentity’)=1
  print ’自增列’
else
  print ’不是自增列’
Select*FROMsys.columnsWhereobject_id=OBJECT_ID(’表名’)
ANDis_identity=1

if exists(select*fromsysindexeswhereid=object_id(’表名’)andname=’索引名’)   
  print  ’存在’   
else   
  print  ’不存在  if exists(select*fromsysindexeswhereid=object_id(’表名’)andname=’索引名’) 
  print  ’存在’ 
else 
  print  ’不存在

Select*FROMsys.sysobjectsWherename=’对象名’ Select*FROMsys.sysobjectsWherename=’对象名’