--Lock a table for exclusive use using application locks
-- not SQL locks

BEGIN TRANSACTION;
DECLARE @result int;
EXEC @result = sp_getapplock @Resource = 'tablename', 
               @LockMode = 'Exclusive';
select @result; -- should be >=0
    EXEC @result = sp_releaseapplock @Resource = 'tablename';
select @result
rollback
//sql/1946