我有两个表,产品和属性。每个产品可以有很多属性!
当我必须找到具有多个属性的产品时,问题就开始了。
select * from `products`
left join `pattributes` on `pattributes`.`products_id` = `products`.`id`
where `products`.`status` = 1
AND `products`.`sold` = 0
AND `products`.`deleted` = 0
AND `products`.`categories_id` = 30
AND `pattributes`.`attributes_id` = 5
AND `pattributes`.`values_id` = 10
AND `pattributes`.`attributes_id` = 4
AND `pattributes`.`values_id` = 15
group by `products`.`id`
order by `products`.`top` desc,
`products`.`id` desc
因此,如果我正在寻找两个或多个 pattributes,它将返回 0 行。但如果我寻找一种属性,它就可以正常工作。
我不是 mysql 专家,不确定是否必须使用左连接来做到这一点。也许有人知道最好的解决方案?
添加了 SQL Fiddle - 也许会更容易 http://sqlfiddle.com/#!2/b3ada0
最佳答案
对多个 pattributes 使用 IN()
,与多个 values_id
相同
select * from `products`
left join `pattributes` on `pattributes`.`products_id` = `products`.`id`
where `products`.`status` = 1
AND `products`.`sold` = 0
AND `products`.`deleted` = 0
AND `products`.`categories_id` = 30
AND `pattributes`.`attributes_id` IN(5 ,4)// if type is varchar then IN('5' ,'4')
AND `pattributes`.`values_id` IN( 10,15 )
group by `products`.`id`
order by `products`.`top` desc,
`products`.`id` desc
关于php - 如果项目有许多(动态)属性,则多个左连接,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/18959759/