DELETE
FROM
    EMP
WHERE
    EMP_CODE IN (
        SELECT
            EMP_INVALID.EMP_CODE
        FROM
            EMP_INVALID
        LEFT JOIN
            EMP ON
            EMP.EMP_CODE = EMP_INVALID.EMP_CODE AND
            EMP.VALID_FLG = 1 AND
            EMP.USER_UPDATE_DATETIME > EMP_INVALID.USER_UPDATE_DATETIME
        WHERE
            EMP.EMP_CODE IS NULL
    )