No, null is in the second part of the UNION. Yes I tried to switch two request (and the same situation) and I must use UNION because in the second request i must do quantinty for different period then in the first query. So, I do sum in another analysis and join everyting on Information desk. That left me.

Thanks Thomas

mistake: Did you know how I can do this with Period. I must write question like this "show me period, product, with quantity=0 or NULL, and how many days quantity was 0 or NULL when day -1 quantity of product was 1

Thanks Thomas I do like you say. Did you know how I can do this with Period. I must write question like this "show me period, product, quantity, and how many when day -1 quantity of produt was 1 OR NULL". For 0/1 column i do this formula: SUM((CASE WHEN "Dane"."Quantity"=0 THEN 1 WHEN "Dane"."Quantity">0 THEN 0 WHEN…