sql db table 중복 찾아내기

sql db table 중복 찾아내기

정규화 하거나 db정비 할 때 씀

SELECT
    gidx, gtype, home_name, away_name, COUNT(*)
FROM
    live_base_game
GROUP BY
    gameidx, gtype, dc_home_tid, dc_away_tid
HAVING 
    COUNT(*) > 1

having 썼을 때 특정 필드만 추출하기.

join을 이용함.

select * from player_map
where source_id in (
select pm.source_id from player_map pm
inner join (
    select *, count(*)
    from player_map
    group by
        source_id
    having count(*) > 1
) pm2 on pm.source_id = pm2.source_id);
 

end.