wecenter彻底删除垃圾注册、提问和文章

wecenter版本为3.3.0
方法：SQL语句；
关键：除question数据表、article数据表、user数据表外，aws_posts_index数据表中的废数据也要删除，否则前台页面垃圾成堆；
删除aws_posts_index这个表中的废数据语句：

delete from aws_posts_index where post_type = 'article' and post_id not in (select id from aws_article);
delete from aws_posts_index where post_type = 'question' and post_id not in (select question_id from aws_question);