我有这样的mysql查询:
$statement=$pdo->prepare("SELECT id AS Activity_ID,type,status,description,
(SELECT SUM(price*worked_hours) FROM tbl_working_hours
WHERE id_act = Activity_ID) AS total_hours FROM tbl_activity");
有两个表:
1- tbl_activity
2-tbl_working_hours
我正在尝试根据另一张表的摘要为每一行创建虚拟列。
谢谢
最佳答案
您可能要使用子查询
SELECT [...], (SELECT COUNT(*) FROM mytable) AS count FROM myothertable
这是我唯一想到的解决方案。问题在于,这种方式在性能方面非常昂贵。