如何处理链接同一实体的多个列

Question

此示例只是我的数据库的架构。我有以下表格称为食谱：

id | author_name | recipe1_id | recipe2_id | recipe3_id

所有配方都与recipes_ingredients表的关系：

id | recipe_id | ingredient1 | ingredient2 | ingredient3

现在我在recipe1_id上做了三个联接，recipe3_id像这样：

SELECT recipe1.ingredient1 as recipe1ingredient1, recipe1.ingredient2 as recipe1ingredient2, recipe1.ingredient3 as recipe1ingredient3, [...]
FROM recipes
INNER JOIN recipe recipe1 ON (recipes.recipe1_id = recipes.id)
INNER JOIN recipe recipe2 ON (recipes.recipe2_id = recipes.id)
INNER JOIN recipe recipe3 ON (recipes.recipe3_id = recipes.id)

为了在 MyBatis 中将 3 个食谱映射到

一个 bean 中，我有三个 resultMaps，将每个食谱映射到包含 3 个成分的配方对象（recipe1、recipe2、recipe3）。

但是：我想把食谱放在一个列表中。我怎样才能做到这一点？

PS：可以肯定的是，我在餐桌食谱和餐桌recipes_ingredients中只有 3 个实体。这永远不会改变，所以我看不出有理由把它放在 n：m 表中。

Answer 1

我认为这会起作用。

<resultMap id="recipe1" type="recipe1">
 ...
</resultMap>
<resultMap id="recipe2" type="recipe2">
 ...
</resultMap>
<resultMap id="recipe3" type="recipe3">
 ...
</resultMap>
<select id="getRecipes" parameterType="list" resultMap="recipe1, recipe2, recipe3">
   SELECT recipe1.ingredient1 as recipe1ingredient1, recipe1.ingredient2 as recipe1ingredient2, recipe1.ingredient3 as recipe1ingredient3, [...]
   FROM recipes
   INNER JOIN recipe recipe1 ON (recipes.recipe1_id = recipes.id)
   INNER JOIN recipe recipe2 ON (recipes.recipe2_id = recipes.id)
   INNER JOIN recipe recipe3 ON (recipes.recipe3_id = recipes.id)
</select>

来源：MyBatis 多个结果集