SQL 获取所有过滤的项目

Question

我在从表中获取数据时遇到问题，其中每个项目都必须匹配另一个表中的过滤器要求，该表中存在 product_id、feature_category_id 和 feature_option_id 之间的关系。

例如。以下是该帮助表中的示例插入：

id = 1
product_id = 10
feature_category_id = 100 - it's name of "feature category" eg. dimensions, weight etc.
feature_option_id = 1001 - it's product value of feature category eg. this product with id 10 have dimensions of 100x100 and it's id in another table is 1001 so it's that value.

现在我需要获得所有符合这些功能选项要求的产品。例如。我从搜索表单中选择给我所有尺寸为 100x100 且重量为 1kg 的产品，因此查询应该做一些事情来检查表格中的这些数据。

我尝试了一些方法，但只有在有 1 个 product.features.feature_category_id 时才有效。如果 where 是 2 个或更多该类型的 where 子句，则返回 0 行。

select distinct 
    "products".*, "product_categories.*"
from 
    "products" 
inner join 
    "product_categories" on "products"."category_id" = "product_categories"."id" 
left join 
    "product_features" on "products"."id" = "product_features"."product_id" 
where 
    "products"."category_id" in (58) and 
    ((product_features.feature_category_id = 1 
      and product_features.feature_option_id = 58) 
     and (product_features.feature_category_id = 46 
          and product_features.feature_option_id = 62))

Answer 1

您可以使用group by和having获得符合您条件的产品：

select p.id
from products p join
     product_categories pc
     on p.category_id = pc."id" left join
     product_features pf
     on p.id = pf.product_id
where p.category_id in (58) and 
      ((pf.feature_category_id = 1 and pf.feature_option_id = 58) or 
       (pf.feature_category_id = 46 and pf.feature_option_id = 62)
      )
group by p.id
having count(distinct feature_category_id) = 2;

如果您需要select 中的更多字段，您可以将它们加入或包含在group by 中。