如何在此選擇內做選擇？ MySQL的

Question

這是我的選擇

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

但我需要從表Product_categories知道列category_url。




我想這一個，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來連接兩個表，你有更多的信息there。如果您有相關的，你可以做到這一點類別的products_items表的外鍵：

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

一個JOIN子句用於行從兩個或多個表結合起來，根據它們之間的相關列。

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