DELETE FROM EMP
WHERE EMP.EMP_CODE IN (
        SELECT EMP.EMP_CODE
        FROM EMP_INVALID
            INNER JOIN EMP ON EMP_INVALID.EMP_CODE = EMP.EMP_CODE
        WHERE not (
                EMP.USER_UPDATE_DATETIME > EMP_INVALID.USER_UPDATE_DATETIME
                AND EMP.VALID_FLG = '1'
            )
    )