IF和LEFT JOIN不工作

Question

我有简单的MySQL查询：

SELECT product.user_id, product.type, product.body, product.created, product.id, product.url, product.name, product.price, images.src 
FROM xn_product AS product 
LEFT JOIN xn_images AS images ON product.id = images.item_id 
WHERE product.active = '1' AND images.type = 'product' AND product.promoted = '1' AND images.main = '1' AND product.url = '". $url "' 

而且我有问题。在images.table中没有product.id查询时不执行。我试图用IF和IF NULL做一些事情，但没有成功。

我想看看它是否是空的images.src覆盖它们为“empty.jpg” OR 1

Answer 1

尝试使用内部连接

SELECT product.user_id, product.type, product.body, product.created, product.id, product.url, product.name, product.price, images.src 
FROM xn_product AS product 
INNER JOIN xn_images AS images ON product.id = images.item_id 
WHERE product.active = '1' AND images.type = 'product' AND product.promoted = '1' AND images.main = '1' AND product.url = '". $url ."'