MySQL은 중복된 데이터를 삭제하고 가장 작은 ID를 유지합니다.

DELETE
FROM
    people
WHERE
    peopleName IN (
        SELECT
            peopleName
        FROM
            people
        GROUP BY
            peopleName
        HAVING
            count(peopleName) > 1
    )
AND peopleId NOT IN (
    SELECT
        min(peopleId)
    FROM
        people
    GROUP BY
        peopleName
    HAVING
        count(peopleName) > 1
)

1 delete from tb where id in (SELECT max(id) from tb GROUP BY user HAVING count(user)>1)

1 delete from tb where id=xx