ALTER TRIGGER [dbo].[tr_Zzzqa_TwTowar_KreskowyEan13]
   ON  [dbo].[tw__Towar]
   AFTER INSERT, UPDATE
AS
DECLARE TrigTempUpdate_Cursor CURSOR FOR
SELECT tw_Id, tw_PodstKodKresk, tw_PLU FROM Inserted
DECLARE @tw_id int, @twkod varchar(20), @tw_plu int
OPEN TrigTempUpdate_Cursor;
FETCH NEXT FROM TrigTempUpdate_Cursor INTO @tw_id, @twkod, @tw_plu 
WHILE @@FETCH_STATUS = 0
BEGIN
	-- PLU --
	if (@tw_plu is null or @tw_plu = 0)
	begin
		SELECT @tw_plu =(SELECT MAX(tw_PLU) FROM tw__towar)
		if (@tw_plu <0) set @tw_plu=0
		set @tw_plu = @tw_plu+1
		
		UPDATE tw__Towar set 
		tw_PLU = @tw_plu
		, tw_urznazwa = replicate('0', 5-len(@tw_plu))+convert(varchar, @tw_plu) + '_' + left(tw_nazwa,18)		
		WHERE tw_id=@tw_id
	end
	else
		UPDATE tw__Towar set 
		tw_urznazwa = replicate('0', 5-len(@tw_plu))+convert(varchar, @tw_plu) + '_' + left(tw_nazwa,18)		
		WHERE tw_id=@tw_id
	-- kod kreskowy --
	if (LEN(@twkod) = 0)
	begin
		declare @maxkod bigint, @kod varchar(13), @i int, @suma int, @mnoznik int;
		
		set @maxkod = isnull(
			(SELECT  cast (MAX(SUBSTRING(tw_PodstKodKresk, 1, 12)) as bigint) as maxkod
			FROM [dbo].[tw__Towar]
			WHERE [tw_PodstKodKresk] LIKE '20[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]'
			), 200000000000);

		set @maxkod = @maxkod +1;
		set @kod = CAST(@maxkod as varchar(12)); set @i = 1; set @suma = 0;
		while(@i <= 12)
		begin
			if (@i % 2 = 0)
					set @mnoznik = 3;
			else
					set @mnoznik = 1;
			set @suma = @suma + @mnoznik * CAST( SUBSTRING(@kod, @i, 1) as int);
			set @i = @i + 1;
		end

		set @suma = @suma % 10;
		if (@suma > 0) 
			set @suma = 10 - @suma;
		set @kod = @kod + CAST(@suma as varchar(1));

		UPDATE tw__Towar SET tw_PodstKodKresk = @kod where tw_Id = @tw_id;
	end

    FETCH NEXT FROM TrigTempUpdate_Cursor INTO @tw_id, @twkod, @tw_plu;
END;

CLOSE TrigTempUpdate_Cursor;
DEALLOCATE TrigTempUpdate_Cursor;