-- hadoop开头的是UCenter表，cdb开头的是BBS部分的表
-- 搜索出所有垃圾用户名:
select `hadoop_members`.`username` from `hadoop_members` left join `cdb_members` on `hadoop_members`.`username`=`cdb_members`.`username` where `cdb_members`.`username` is null;
select `hadoop_members`.`username` from `hadoop_members` where not exists (select `cdb_members`.`username` from `cdb_members` where `hadoop_members`.`username`=`cdb_members`.`username`);
-- 搜索出垃圾用户个数:
select count(`hadoop_members`.`username`) from `hadoop_members` left join `cdb_members` on `hadoop_members`.`username`=`cdb_members`.`username` where `cdb_members`.`username` is null;
select count(`hadoop_members`.`username`) from `hadoop_members` where not exists (select `cdb_members`.`username` from `cdb_members` where `hadoop_members`.`username`=`cdb_members`.`username`);
-- 删除垃圾用户
delete from `hadoop_members` where not exists (select 1 from `cdb_members` where `hadoop_members`.`username`=`cdb_members`.`username`);
本文转自eyjian 51CTO博客，原文链接：http://blog.51cto.com/mooon/909768，如需转载请自行联系原作者
