(MSSQL) 유니크 걸기

--한개같이유니크

alter table play.ranking

add constraint AK_play_ranking_login_no unique (login_no)



--두개같이유니크

alter table play.ranking

add constraint AK_play_ranking unique (login_no, login_nickname)





https://msdn.microsoft.com/ko-kr/library/ms190024(v=sql.120).aspx