MySQL-“子查询返回多于1行”错误

Question

I have two tables :

ingredients

|   id   |       iName      |
-----------------------------
|   101  |     Curcumin     |
|   102  |     Riboflavin   |
|   103  |     Protease     |
|   104  |    Tartrazine    |
|   105  |      Amylase     |

foodproduct_ingredient

|  foodproduct_id  |  ingredient_id   |
---------------------------------------
|         1        |        101       |
|         1        |        102       |
|         1        |        104       |

And I just want to get list iName for every single foodproduct. For example, when I want to get iName in foodproducts.id = 1 must be

|        iName       |
----------------------
|      Curcumin      |
|      Riboflavin    |
|      Tartrazine    |

I have tried to insert query :

SELECT ingredients.iName FROM ingredients INNER JOIN foodproduct_ingredient 
        ON ingredients.id = foodproduct_ingredient.foodProduct_id 
        WHERE ingredients.id = 
        (SELECT foodproduct_ingredient.ingredient_id FROM foodproduct_ingredient INNER JOIN foodproducts 
        ON foodproducts.id = foodproduct_ingredient.foodProduct_id 
        WHERE foodproducts.id = 1)

but it returns subquery returns more than 1 row

Can somebody help me? Thanks :)

*Note : there is table foodproducts just for join to get id of foodproducts

Answer 1

I think you should use IN clause

SELECT ingredients.iName FROM ingredients INNER JOIN foodproduct_ingredient 
    ON ingredients.id = foodproduct_ingredient.foodProduct_id 
    WHERE ingredients.id In 
    (SELECT foodproduct_ingredient.ingredient_id FROM foodproduct_ingredient INNER JOIN foodproducts 
    ON foodproducts.id = foodproduct_ingredient.foodProduct_id 
    WHERE foodproducts.id = 1)

By the way you wont even need subquery i guess. Try to use below query

select i.iName from ingredients i
join foodproduct_ingredient fi
on fi.ingredient_id = i.id
where fi.foodproduct_id = 1