使用来自两个表的内部连接的无效记录

Question

我从 codeigniter

生成了这个 sql 语句

SELECT * FROM (`products`) LEFT JOIN `products_attributes` ON `products_attributes`.`product_id` = `products`.`id` WHERE `products`.`category` = '1' AND `products`.`sub_category` = '1' AND `products_attributes`.`attribute_id` = '3' AND `products_attributes`.`attribute_id` = '4' AND `products_attributes`.`attribute_id` = '5' GROUP BY `products`.`id`

我有这些表格

产品： products_attributes :

我只需要获取所有属性的产品，所以如果属性是3,4,5我会获取产品id = 1，如果属性是3,4,5,6我不会获取产品 ID = 1

Answer 1

试试这个：

SELECT * FROM (`products`) 
LEFT JOIN `products_attributes` 
ON `products_attributes`.`product_id` = `products`.`id` 
WHERE `products`.`category` = 1 
AND `products`.`sub_category` = 1 
AND `products_attributes`.`attribute_id` IN (3, 4, 5) 
GROUP BY `products`.`id`

Answer 2

您的 sql 查询完全错误。你所做的是：给我记录 attribute_id = 3 AND attribute_id = 4 AND attribute_id = 5 AND attribute_id = 6。一行不能同时等于 3 和 4时间。您需要的东西可以通过许多不同的方式实现。例如：

SELECT
    products.id
FROM  products

    JOIN products_attributes ON products_attributes.product_id = products.id
WHERE
    products.category = '1'
    AND `products_attributes`.`attribute_id` IN (3,4,5,6)


GROUP BY
    products.id
HAVING COUNT(DISTINCT `products_attributes`.`attribute_id`) = 4

如果您只指定 IN ...，那么它将获取至少有 1 个这样的记录的所有记录 attribute_id

使用来自两个表的内部连接的无效记录

invalid records using inner join from two tables

php

sql

codeigniter

codeigniter-2