仅当列的所有元素都在另一个表中时才匹配

Question

I've made a little database in SQL that as 2 tables Product ( Name , Ingredient and Available ( Ingredient ):

|     Product         | Available  |
|  Name  | Ingredient | Ingredient |
|   1    |      a     |      a     |
|   1    |      b     |      c     |
|   2    |      a     |
|   2    |      c     |

I want the name of a product only if ALL its ingredients are inside the Available table.
For the previous example, the result should be: Product "2" and not Product "1", because I don't have the ingredient "b" in the Available table.

Thanks for the help

Answer 1

You can try with left join (to figure out which Products don't have necessary Ingredients ) and group by + having to filter Products that have at least one missing Ingredient :

select p.Name 
from Products p 
left join Available a on a.Ingredient = p.Ingredient
group by p.Name
having sum(a.Ingredient is null) = 0

Answer 2

You can try something like this also:

WITH TEMP_PRODUCTS AS
(
    SELECT NAME, COUNT(1) AS NUMBER_OF_INGREDIENTS
      FROM PRODUCT
  GROUP BY PRODUCT
)
SELECT PRD.NAME, COUNT(1) AS NUMBER_OF_AVAILABLE_INGREDIENTS
  FROM PRODUCT PRD
  JOIN TEMP_PRODUCTS TMP ON PRD.NAME = TMP.NAME
 WHERE EXISTS (SELECT 1 
                 FROM INGREDIENT ING
                WHERE ING.INGREDIENT = PRD.INGREDIENT)
 GROUP BY PRD.NAME
 HAVING COUNT(1) = TMP.NUMBER_OF_INGREDIENTS;