delete from table_name t1 where t1.rowid<>(
select max(rowid) from table_name t2 where t1.col1=t2.col1 and t1.col2=t2.col2 .....)
select max(rowid) from table_name t2 where t1.col1=t2.col1 and t1.col2=t2.col2 .....)
1.create table tabname_bak as select distinct * from tabname;
2.truncate table tablname;
3.drop table tabname;
4.create table tabname as select * from tabname_baka;