Question

表产品：

id|name
-------
1 |computer
2 |microwave
3 |transl

表product_features：

feature          | id_product | feature_value
------------------------------------
count_of_buttons | 1          | 1
count_of_buttons | 2          | 2
count_of_buttons | 3          | 1
color            | 1          | white
color            | 2          | white
color            | 3          | black

请问如何用一个按钮获得所有白色产品？非常感谢你！

Answer 1

select product.*

from product
  join product_features as buttons
    on buttons.id_product = product.id
  join product_features as color
    on color.id_product = product.id

where buttons.feature_value = '1'
  and buttons.feature = 'count_of_buttons'

  and color.feature_value = 'white'
  and color.feature = 'color';

Answer 2

select
    p.id
    p.name
from
    products p
    join (select * from product_features where feature = 'color') colors on (p.id=colors.id_product)
    join (select * from product_features where feature = 'count_of_buttons') buttons on (p.id=buttons.id_product)
where
    colors.feature_value = 'white'
    and buttons.feature_value = 1

您可以考虑重新组织product_features表，以便为每个要素（即color列和count_of_buttons列）分别设置一列，以便每个产品都有一行。事实上，它可能都在产品表中。

Answer 3

选择 p.id 来自产品p 加入product_features pf ON p.id = pf.id 在哪里pf.feature_value ='white'AND pf.count_of_buttons = 1

Answer 4

select p.id, p.name from products p inner join product_features ON p.id=id_product where feature_value='white' and feature='color' and count_of_buttons=1

条件（在哪里）mysql

4 个答案: