[英]How can I combine these 2 SQL Queries into one
I am having some trouble figuring out how to combine these 2 queries. 我在弄清楚如何组合这两个查询时遇到了一些麻烦。
$get_id = $psk->goqueryvalue("SELECT `categoryid` FROM `products` WHERE `seo_title` = '{$url_title}'");
$get_category = $psk->goqueryvalue("SELECT `title` FROM `categories` WHERE `id` = '{$get_id}'");
($psk->goqueryvalue just returns a single value.) ($ psk-> goqueryvalue仅返回一个值。)
Thanks 谢谢
SELECT c.title # also c.id if you need it
FROM categories c, products p
WHERE c.id = p.categoryid
AND p.seo_title = '{$url_title}'
Try something like 尝试类似
SELECT `categoryid`, `title` FROM `products`
LEFT JOIN `categories` ON `products`.`categoryid` = `categories`.`id`
WHERE `products`.`seo_title` = '{$url_title}'
Try something like 尝试类似
$get_category = $psk->goqueryvalue("SELECT `title` FROM `categories` WHERE `id` = (SELECT `categoryid` FROM `products` WHERE `seo_title` = '{$url_title}'");
OR 要么
$get_category = $psk->goqueryvalue("SELECT `title` FROM `categories` INNER JOIN `products` ON
`categories.id` = `products.categoryid` WHERE `seo_title` = '{$url_title}'");
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