Query
CREATE TABLE shopping_list_recipe_reference (
created_at DATETIME,
update_at DATETIME,
id CHAR(32) NOT NULL,
shopping_list_id CHAR(32) NOT NULL,
recipe_id CHAR(32),
recipe_quantity FLOAT NOT NULL,
PRIMARY KEY (id, shopping_list_id),
FOREIGN KEY(recipe_id) REFERENCES recipes (id),
FOREIGN KEY(shopping_list_id) REFERENCES shopping_lists (id)
)