Question

我有树桌：

配方：

id | title | ....

recipe_ingredients：

recipe_id | ingredient_id

成分：

id | ingredient

每种食谱都含有与之相关的成分。

我写了一个查询，通过成分ID获取食谱ID，成分匹配计数，该配方的成分总数：

SELECT recipes.id, recipes.title, ing_match_count,
    (
    SELECT count(id)
    FROM recipe_ingredients as ri
    WHERE ri.recipe_id = recipes.id
    ) as recipe_ing_count
FROM recipes
RIGHT JOIN (
    SELECT recipe_id, ingredients_id, COUNT(*) AS ing_match_count
    FROM recipe_ingredients
    WHERE ingredients_id IN (19, 25, 30, 40)
    GROUP BY recipe_id
) AS ri
ON recipes.id = ri.recipe_id
ORDER BY ing_match_count DESC

问题是，我无法使用其他成分ID排除食谱。上面的查询搜索具有19,25,30,40个成分ID的配方。但我想排除食谱，例如22和23种成分。

因此，如果食谱有19和22成分id，它将不会显示。

Answer 1

我喜欢将group by与having子句中的条件用于这些类型的查询。我发现这是最灵活的appraoch。

SELECT r.id, r.title,
       SUM(ingredients_id IN (19, 25, 30, 40)) as ing_match_count,
       COUNT(*) as recipe_ing_count
FROM recipes r JOIN
     recipe_ingredients  ri
     ON ri.recipe_id = recipes.id
GROUP BY r.id, r.title
HAVING ing_match_count > 0 AND
       SUM(ingredients_id in (22, 23)) = 0;

获取不含X成分的食谱

1 个答案: