由于目前还广泛使用着SQLServer2000，很多公司又想使用新的SQLServer，从而直接【分离/附加】或者【备份/还原】数据库，在不同版本之间存放。往往就会遇到版本不兼容的问题。前几天遇到了从我本机2008R2上备份的一个数据库还原到2008上面时报错：

从运行版本10.50.2500（2008R2是10.50）和10.00.1600（2008是10.00）中可以看出这个版本不兼容问题，大部分情况下，从低版本升级到高版本，只要不是跨度太大，如2000升级到2012，都不会怎么报错。除非使用了一些新版本不兼容的特性如*=来实现left join的语句。但是就像上图那样，从高版本还原到低版本的时候，问题就出现了，而且几乎一定会报错。

下面给出几个小建议，例子是从2008 降级到2005：

方法一：使用图形化操作（GUI），打开SSMS(SQL Server Management Studio)

步骤1：右键你要降级的数据库，按下图选择：

步骤2：在对话框中选择：

   步骤3：在【高级】中选择下图：

步骤4：把脚本保存起来，然后在SQLServer2005中运行脚本。

步骤5：通过【任务】→【导入数据】，把数据从2008导入到使用脚本创建的库上如下图，就完成了：

方法二：使用系统自带的存储过程实现：sp_dbcmptlevel ——将某些数据库行为设置为与指定的 SQL Server 版本兼容

下面是其内部实现代码：

SET QUOTED_IDENTIFIER ON
 SET ANSI_NULLS ON
 GO
 create procedure sys.sp_dbcmptlevel			-- 1997/04/15
 	@dbname sysname = NULL,					-- database name to change
 	@new_cmptlevel tinyint = NULL OUTPUT	-- the new compatibility level to change to
 as
 	set nocount    on
 
 	declare @exec_stmt nvarchar(max)
 	declare @returncode	int
 	declare @comptlevel	float(8)
 	declare @dbid int					-- dbid of the database
 	declare @dbsid varbinary(85)		-- id of the owner of the database
 	declare @orig_cmptlevel tinyint		-- original compatibility level
 	declare @input_cmptlevel tinyint	-- compatibility level passed in by user
 		,@cmptlvl80 tinyint				-- compatibility to SQL Server Version 8.0
 		,@cmptlvl90 tinyint				-- compatibility to SQL Server Version 9.0
 		,@cmptlvl100 tinyint				-- compatibility to SQL Server Version 10.0
 	select  @cmptlvl80 = 80,
 			@cmptlvl90 = 90,
 			@cmptlvl100 = 100
 
 	-- SP MUST BE CALLED AT ADHOC LEVEL --
 	if (@@nestlevel > 1)
 	begin
 		raiserror(15432,-1,-1,'sys.sp_dbcmptlevel')
 		return (1)
 	end
 
 	-- If no @dbname given, just list the valid compatibility level values.
 	if @dbname is null
 	begin
 	   raiserror (15048, -1, -1, @cmptlvl80, @cmptlvl90, @cmptlvl100)
 	   return (0)
 	end
 
 	--  Verify the database name and get info
 	select @dbid = dbid, @dbsid = sid ,@orig_cmptlevel = cmptlevel
 		from master.dbo.sysdatabases
 		where name = @dbname
 
 	--  If @dbname not found, say so and list the databases.
 	if @dbid is null
 	begin
 		raiserror(15010,-1,-1,@dbname)
 		print ' '
 		select name as 'Available databases:'
 			from master.dbo.sysdatabases
 		return (1)
 	end
 
 	-- Now save the input compatibility level and initialize the return clevel
 	-- to be the current clevel
 	select @input_cmptlevel = @new_cmptlevel
 	select @new_cmptlevel = @orig_cmptlevel
 
 	-- If no clevel was supplied, display and output current level.
 	if @input_cmptlevel is null
 	begin
 		raiserror(15054, -1, -1, @orig_cmptlevel)
 		return(0)
 	end
 
 	-- If invalid clevel given, print usage and return error code
 	-- 'usage: sp_dbcmptlevel [dbname [, compatibilitylevel]]'
 	if @input_cmptlevel not in (@cmptlvl80, @cmptlvl90, @cmptlvl100)
 	begin
 		raiserror(15416, -1, -1)
 		print ' '
 		raiserror (15048, -1, -1, @cmptlvl80, @cmptlvl90, @cmptlvl100)
 		return (1)
 	end
 
 	--  Only the SA or the dbo of @dbname can execute the update part
 	--  of this procedure sys.so check.
 	if (not (is_srvrolemember('sysadmin') = 1)) and suser_sid() <> @dbsid
 		-- ALSO ALLOW db_owner ONLY IF DB REQUESTED IS CURRENT DB
 		and (@dbid <> db_id() or is_member('db_owner') <> 1)
 	begin
 		raiserror(15418,-1,-1)
 		return (1)
 	end
 
 	-- If we're in a transaction, disallow this since it might make recovery impossible.
 	set implicit_transactions off
 	if @@trancount > 0
 	begin
 		raiserror(15002,-1,-1,'sys.sp_dbcmptlevel')
 		return (1)
 	end
 
 	set @exec_stmt = 'ALTER DATABASE ' + quotename(@dbname, '[') + ' SET COMPATIBILITY_LEVEL = ' + cast(@input_cmptlevel as nvarchar(128))
 
 	-- Note: database @dbname may not exist anymore
 	exec(@exec_stmt)
 
 	select @new_cmptlevel = @input_cmptlevel
 
 	return (0) -- sp_dbcmptlevel
 GO
 

语法

sp_dbcmptlevel [ [ @dbname = ] name ] 
     [ , [ @new_cmptlevel = ] version ]
 

返回代码值

注意事项：