[Database] 문자열 합치기 (CONCAT, GROUP_CONCAT)

컬럼 합치기

SELECT CONCAT(e.email, '@', e.email2) as [E-mail]
FROM userinfo as u , userinfo_mail as e
WHERE u.idx = e.mem_idx;

 

하나의 컬럼 값 합치기

SELECT GROUP_CONCAT(email) AS mail FROM administrators