如果需要更新固定的字符串，可以一句sql搞定：

update pre_forum_post set message=replace(message,'被替换的','新上位的');

wordpress 的话，如果改了域名，文章里的域名地址要改一下：

UPDATE wp_options SET option_value = replace(option_value, 'old.com', 'new.com');

UPDATE wp_posts SET post_content = replace(post_content, 'old.com', 'new.com');

UPDATE wp_posts SET guid = replace(guid, 'old.com', 'new.com');

切记！做之前备份哦！

discuz修改标题
update pre_forum_post set message=replace(message,'http://moneyslow.com','https://moneyslow.com') where message like '%http:%';
update pre_forum_thread set subject=replace(subject,'aaaaa','bbbbbb') where subject like '%aaaaa%';