create table 临时表 as select a.字段1,a.字段2,max(a.rowid) as dataid from 原表 a group by a.字段1,a.字段2;
delete from 原表 a where a.rowid != (select b.dataid from 临时表 b where a.字段1 = b.字段1 and a.字段2 = b.字段2); commit;
delete from 表名 t where t.rowid not in (select max(rowid) from 表名 t1 group by t1.字段1, t1.字段2);