使用null值创建连接

Question

我有一个表“产品”和一个表“订单” Orders表包含以下字段：“id_products”和“id_users” 加入这两个表然后写：

SELECT * FROM products as p LEFT JOIN orders as o ON p.id_products=o.id_products

我想创建一个JOIN，其中包含您订购ID为1的用户的所有产品以及仍需订购的产品。

编辑：

SELECT * FROM products LEFT JOIN orders 
ON products.id_products= orders.id_products
WHERE user_id = 1 OR user_id IS NULL

Answer 1

SELECT * FROM products LEFT JOIN orders 
ON products.id_products= orders.id_products
Where user.id = 1

Answer 2

不

SELECT * FROM products as p LEFT OUTER JOIN orders as o ON p.id_products=o.id_products  
where id_users = 1

做你想做的事吗？