select commend_date, commender_id, stock_code,stock_name,issue_channelfrom commendstock awhere (a.commend_date, a.commender_id, a.stock_code)in (select commend_date, commender_id, stock_codefrom commendstock group by commend_date, commender_id, stock_code having count(*)>1) --and rowid not in(select min(rowid) from commendstock -- group by commend_date, commender_id, stock_code --having count(*)>1)order by commend_date,commender_id,stock_code
;
现在要删除表中重复的记录。条件是：3个字段重复，同时比较第4个字段的值，保留值比较小的那一条例如：字段1 字段2 字段3 字段4数值1 数值2 数值3 1数值1 数值2 数值3 4因为前3个字段都重复，第一条记录的字段4值为1，比第二条记录的字段4的值小，所以删除第二条，保留第一条。
select * from commendstock t where exists(select 1 from commendstock t2 where t.commend_date=t2.commend_date and t.commender_id=t2.commender_id and t.stock_code=t2.stock_code and t.commend_type>t2.commend_type)
