插入或更新

Question

我的代码使用另一个表中的值在一个查询中多次更新同一行。如何在一个查询中更新或创建新记录？如果没有记录“ forum_users_posts_in”与匹配数据该怎么办

userid 
idcat
idcustom
create a new record (t.posts = 1)

如果存在这样的记录，则仅更新（t.posts = t2.sum_total）

UPDATE #__forum_users_posts_in AS t
            JOIN (
            SELECT
            userid, count(*) AS sum_total
            FROM
            #__forum_messages AS t2
            WHERE
            T2.thread = '.$topicId.' and hold = 0
            GROUP BY
            t2.userid
            ) AS t2 ON t.userid = t2.userid and (idcat = '.$cat->id.' or idcustom = '.$selectcustom1.')
            SET  t.posts =  t.posts + t2.sum_total

Answer 1

您可以尝试使用此方法来创建或编辑行

INSERT INTO `table` (`columns`) VALUES
(...)
ON DUPLICATE KEY UPDATE
`column` = VALUES (`column`);