Question

Given the following tables:

Recipes
| id | name
| 1  | 'chocolate cream pie'
| 2  | 'banana cream pie'
| 3  | 'chocolate banana surprise'

Ingredients
| id | name
| 1  | 'banana'
| 2  | 'cream'
| 3  | 'chocolate'

RecipeIngredients
| recipe_id | ingredient_id
|     1     |      2
|     1     |      3
|     2     |      1
|     2     |      2
|     3     |      1
|     3     |      3

How do I construct a SQL query to find recipes where ingredients.name = ‘chocolate’ and ingredients.name = ‘cream’?

Answer 1

This is called relational division. A variety of techniques are discussed here.

One alternative not yet given is the double NOT EXISTS

SELECT r.id, r.name
FROM Recipes r
WHERE NOT EXISTS (SELECT * FROM Ingredients i
                  WHERE name IN ('chocolate', 'cream')
                  AND NOT EXISTS
                      (SELECT * FROM RecipeIngredients ri
                       WHERE ri.recipe_id = r.id
                       AND ri.ingredient_id = i.id))