Question

我有3个表，食谱， recipes_instructions ， recipes_ingredients ，第一个是主要的，其余的是指 recipe_id 来自食谱表格。

我编写下面的代码试图让一些工作正常，现在它正在检索我想要的所有数据，我只是不确定如何通过它的组来组织它，我认为 GROUP_CONCAT 是要走的路，但不知道如何去做。

这是我想要的结果：

Array
(
    [id] => 1
    [title] => Citrus Shortbread Cookies
    [instruction_group] => Array (
        [0] => Divide the dough into 2 equal portions...
        [1] => Preheat an oven to...
        [2] => Remove wax paper, and...
        [3] => Bake in the preheated oven...
    )
    [ingredients_group] => Array (
        [0] => 1 cup (230g) butter
        [1] => 1 teaspoon vanilla extract
        [2] => 2 cups (250g) all-purpose flour
        [3] => Zest of one lime
        [4] => 1/2 cup (65g) icing sugar
    )
)

我尝试了什么：

1：这是我得到的最接近的东西，它仍然有重复的结果，它甚至从未指定的配方ID中检索数据库中的所有数据。

http://sqlfiddle.com/#!9/725468/33

SELECT *
  FROM recipes 
INNER JOIN
  (SELECT recipe_id, GROUP_CONCAT(instruction) instruction_group FROM recipe_instructions) 
  as instructionscombined 
  on recipes.id = instructionscombined.recipe_id
INNER JOIN 
  (SELECT recipe_id, GROUP_CONCAT(ingredients) ingredient_group FROM recipe_ingredients)
  as ingredientscombined
  on recipes.id = ingredientscombined.recipe_id
WHERE recipes.id = 1

2：结果重复，表中的所有数据都已从未指定配方ID的数据中返回。

http://sqlfiddle.com/#!9/725468/39

SELECT *, GROUP_CONCAT(inst.instruction), GROUP_CONCAT(ingr.ingredients) FROM recipes 
INNER JOIN recipe_instructions as inst on recipes.id = inst.recipe_id
INNER JOIN recipe_ingredients as ingr on recipes.id = ingr.recipe_id
WHERE recipes.id = 1

修改至于查询返回行的所有数据的问题是因为我在嵌套选择中没有显式。

这解决了问题，但我仍然得到重复的recipe_id列

http://sqlfiddle.com/#!9/725468/64

SELECT *
  FROM recipes 
INNER JOIN
  (SELECT recipe_id, GROUP_CONCAT(instruction) instruction_group 
   FROM recipe_instructions
   WHERE recipe_id = 1
  )
  as instructionscombined 
  on recipes.id = instructionscombined.recipe_id
INNER JOIN 
  (SELECT recipe_id, GROUP_CONCAT(ingredients) ingredient_group 
   FROM recipe_ingredients
   WHERE recipe_id = 1
  )
  as ingredientscombined
  on recipes.id = ingredientscombined.recipe_id
WHERE recipes.id = 1
GROUP BY recipes.id

第二次编辑：

所以......我学到的是mysql没有数组功能，所以我现在正在做的是使用上面的查询，并使用 GROUP_CONCAT分离group_concat（说明SEPARATOR \ '__ \'）（我不得不逃避'因为我正在使用php），然后运行一个while循环并爆炸组。

Answer 1

尝试一下：

SELECT 
    a.*,
    GROUP_CONCAT(DISTINCT b.instruction ORDER BY b.instruction_id) as `instructions`,
    GROUP_CONCAT(DISTINCT c.ingredients ORDER BY c.ingredient_id) as `ingredients`
FROM recipes a
JOIN recipe_instructions b
ON a.id = b.recipe_id
JOIN recipe_ingredients c
ON a.id = c.recipe_id
GROUP BY a.id
ORDER BY a.title

以下是此查询的SQL Fiddle。

如何使用MySQL在单个查询中对来自1-many关系的数据进行分组？

1 个答案: