Select title,Count(*) From ucms_article Group By title Having Count(*) > 1
delete from ucms_article where id not in( select * from (select max(id) from ucms_article group by title ) as tmp);
ALTER TABLE `ucms_article` ADD unique(`title`);
delete from ucms_article where title not in ( select * from (select max(title) from ucms_article group by title having count(title)>1) b);
