Limit number of versions in sharepoint

Declare @cmd VarChar(1000) , 
@LeafCount varchar(50),
@ID varchar (100) ,
@LeafName varchar (50),
        @versionNum int


declare Timeval cursor for
SELECT     DocVersions.Id AS ID, Docs.LeafName AS LeafName, COUNT(Docs.LeafName) AS LeafCount
FROM       DocVersions INNER JOIN
           Docs ON DocVersions.Id = Docs.Id
GROUP BY DocVersions.Id, Docs.LeafName

Open Timeval

FETCH NEXT from Timeval INTO @ID, @LeafName, @LeafCount
WHILE @@FETCH_STATUS = 0

Begin
--Print '{' + @ID + '}'

if @LeafCount > 4

SELECT @versionNum = MIN(version) FROM DocVersions WHERE Id = '{' + @ID + '}'

DELETE FROM DocVersions
WHERE  version = @versionNum
        AND  Id = '{' + @ID + '}'

FETCH NEXT from Timeval INTO @ID, @LeafName, @LeafCount

end

close Timeval
deallocate Timeval