只需创建另一个 cron:

Just create another cron:

0 3 * * * find $HOME/db_backups -name "db_name*.sql" -mtime +30 -exec rm {} ; >> $HOME/db_backups/purge.log 2>&1

它将查找所有超过 30 天的备份并删除它们.

It will find all backups older than 30 days and delete them.