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。

09-09 20:32
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