[sql] SQL select 문에서 Order By 1의 목적은 무엇입니까?

직장에서 오래된 코드를 읽고 있는데 order by 1절이 있는 여러 가지 견해가 있음을 알았습니다 . 이것이 무엇을 달성합니까?

예:

Create view v_payment_summary AS
SELECT A.PAYMENT_DATE,
       (SELECT SUM(paymentamount)
          FROM payment B
         WHERE PAYMENT_DATE = B.PAYMENT_DATE
           and SOME CONDITION) AS SUM_X,
       (SELECT SUM(paymentamount)
          FROM payment B
         WHERE PAYMENT_DATE = B.PAYMENT_DATE
           and SOME OTHER CONDITION) AS SUM_Y
FROM payment A
ORDER BY 1;

답변

ORDER BY 1

ORDER BY A.PAYMENT_DATE

select cola
  from tablea
union
select colb
  from tableb
order by 1;

SELECT Name, Name FROM Segment ORDER BY 1