SQLServer数据库从高版本降级到低版本实例详解

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

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

[ @dbname = ] name