delete glt_entity_tmp from glt_entity_tmp,(select idd from glt_entity_tmp group by nam having count(*) > 1 ) as t2
二、以二个或以上字段来唯一确定一条记录，可以用以下SQL来删除，但要注意每条记录中必须有第三个字段来唯一确定这条记录（使用max删除）
delete gbi_pd_theme_new_tmp from gbi_pd_theme_new_tmp,(select new_code,the_code,max(the_new_code) as the_new_code from gbi_pd_theme_new_tmp group by new_code,the_code having count(*) > 1) as t2
where gbi_pd_theme_new_tmp.new_code=t2.new_code and gbi_pd_theme_new_tmp.the_code=t2.the_code and gbi_pd_theme_new_tmp.the_new_code=t2.the_new_code
注意：如果是有多于2条重复的记录，要执行多次
因为此例子中每条记录有一个唯一的字段the_new_code，所以可以用max来删除重复记录
