數據庫中重複數據查詢和刪除

重複數據查詢:

select id_number,count(id_number) from human_info group by id_number having count(id_number)>1;

 

刪除重複數據:

按rowid,保留rowid最大的數據

delete from human_info where id_number in (select id_number from human_info group by id_number having count(id_number)>1) and rowid not in (select max(rowid) from human_info group by id_number having count(id_number)>1);

 

按入庫日期,保留最大日期數據

delete from human_info where id_number in (select id_number from human_info group by id_number having count(id_number)>1) and insert_time not in (select max(insert_time) from human_info group by id_number having count(id_number)>1);

delete from human_info where insert_time not in (select max(insert_time) from human_info group by id_number having count(id_number)>1);(這個貌似也能夠).