我试图在下面的查询中添加表 t4 的计数,而不限制结果。就像是:
COUNT(t4.offer_to_purchase_id) AS count
但这将结果限制为仅出现在 t4 中的那些服务,尽管有左连接
$sql = "SELECT s.*, q.categories, t4.*, payments.*, quotes.*
FROM services s
LEFT JOIN
(
SELECT sc.service_id, GROUP_CONCAT(c.name) categories
FROM services_categories sc JOIN categories c
ON sc.cat_id= c.cat_id
GROUP BY sc.service_id
) q ON s.service_id = q.service_id
LEFT JOIN offers_to_purchase t4
ON s.service_id = t4.service_id
LEFT JOIN quotes ON quotes.service_id = s.service_id
LEFT JOIN payments ON payments.service_id = s.service_id
WHERE s.user_id = $user_id";
我怎样才能做到这一点?