SELECT all orders with more than one item and check all items status

Question

I have 2 tables:

Orders:

Id   |  Status
-----+--------
 1   |      OK
 2   | WAITING
 3   | WAITING
 4   |      OK
 5   |      OK
 6   |      OK
<         


        

Answer 1

SELECT O.Id 
FROM Orders O 
JOIN Order_details OD ON O.Id=OD.Order_Id
WHERE O.Status='OK'
GROUP BY O.Id
HAVING count(DISTINCT OD.Id)>1
AND SUM(CASE WHEN OD.Status NOT IN ('S1','S2') 
             THEN 1 
             ELSE 0 
        END) = 0