如何筛选具有多个条件 MySQL 的行

Question

我有一个 table 包含我的产品详细信息

+-----+------------+--------+-------+---------+
| id  | product_id | cat_id | field | value   |
+-----+------------+--------+-------+---------+
| 166 |        121 |     12 | model | Core i7 |
| 164 |        121 |     12 | brand | Intel   |
| 172 |         15 |     12 | model | Core i5 |
| 170 |         15 |     12 | brand | Intel   |
+-----+------------+--------+-------+---------+
4 rows in set

现在我想编写一个查询，在以下条件下为我提供 product_id(s)：

品牌=英特尔
型号=酷睿i7

我试过这个，但它没有 returns 任何行，我想我应该使用 JOIN。

SELECT * FROM `wp_product_details_fields` 
WHERE `field` = 'brand' AND `value` = 'Intel' AND `field` = 'model' AND `value` = 'Core i7'

Answer 1

使用OR

你应该像下面这样尝试：

SELECT * FROM `wp_product_details_fields` 
WHERE (`field` = 'brand' AND `value` = 'Intel') OR (`field` = 'model' AND `value` = 'Core i7')

Answer 2

使用group by和having:

select product_id
from wp_product_details_fields
where field in ('model', 'brand')
group by product_id
having max(field = 'model' and value = 'Core i7') = 1
   and max(field = 'brand' and value = 'Intel'  ) = 1

或者更好的是，使用元组相等：

select product_id
from wp_product_details_fields
where (field, model) in ( ('model', 'Core i7'), ('brand', 'Intel') )
group by product_id
having count(*) = 2

Answer 3

我认为你必须重新考虑你的数据库结构，我建议你有模型字段和品牌字段。所以你可以做简单的 'select' 查询。并过滤行。

如何筛选具有多个条件 MySQL 的行

How to filter rows that has multiple condition MySQL

mysql

sql

aggregate-functions

where-clause

having-clause