Question

我有一个表格，其中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，让我在以下情况下获得product_id：

品牌=英特尔
模型=酷睿i7

我已经尝试过了，但是它没有返回任何行，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，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 2

使用OR

您应该尝试如下操作：

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

Answer 3

我认为您必须重新考虑您的数据库结构，我建议您拥有模型领域和品牌领域。因此您可以执行简单的“选择”查询。并过滤行。

如何过滤具有多个条件的MySQL行

3 个答案: