如何在此选择内做选择？ MySQL的

Question

这是我的选择

SELECT id, name, price, category, url, image1 FROM `Products_items` WHERE active='y' and stockCount >= 1 ORDER BY views DESC 

但我需要从表Product_categories知道列category_url。




我想这一个，但不工作

SELECT id, name, price, category, url, image1 FROM `Products_items` WHERE active='y' and stockCount >= 1 ORDER BY views DESC 
SELECT url FROM Product_categories WHERE id=Products_items.category 

Answer 1

您可以使用JOIN来连接两个表，你有更多的信息there。如果您有相关的，你可以做到这一点类别的products_items表的外键：

SELECT a.id, a.name, a.price, a.category, b.url, a.image1 
FROM `Products_items` a 
LEFT JOIN Product b ON a.category_id = b.id 
WHERE a.active='y' and a.stockCount >= 1 ORDER BY a.views DESC 

Answer 2

一个JOIN子句用于行从两个或多个表结合起来，根据它们之间的相关列。

SELECT * FROM Products_items as items JOIN Product_categories as categories ON items.category = categories.id;