前提：表user_info，字段Id(主键)，age，sex
删除除主键id外，age和sex字段重复的数据，只留有rowid最小的记录
delete from user_INFO a where (a.age,a.sex) in (select age，sex group by age，sex having count(*) > 1) and rowid not in (select min(rowid) from user_INFO group by age，sex having count(*)>1);