★VER2.0★[프로그래머스 ORACLE SQL]오프라인/온라인 판매 데이터 통합하기

https://school.programmers.co.kr/learn/courses/30/lessons/131537

프로그래머스

VERSION 2.0

SELECT TO_CHAR(SALES_DATE , 'YYYY-MM-DD') AS SALES_DATE , PRODUCT_ID , USER_ID , SALES_AMOUNT FROM

(SELECT SALES_DATE , PRODUCT_ID , USER_ID , SALES_AMOUNT FROM ONLINE_SALE
union
SELECT SALES_DATE, PRODUCT_ID , null USER_ID, SALES_AMOUNT FROM OFFLINE_SALE) --NULL 생성하는 열 함수

WHERE TO_CHAR(SALES_DATE , 'YYYY-MM') ='2022-03'
ORDER BY SALES_DATE ASC , PRODUCT_ID ASC , USER_ID ASC

==> 열에 NULL 값 부여위해서는 앞에 NULL 값을 붙인다!!

 

 

VERSION 1.0

SELECT to_char(SALES_DATE, 'yyyy-mm-dd'),PRODUCT_ID, user_id, SALES_AMOUNT
from(
SELECT SALES_DATE,PRODUCT_ID, USER_ID, SALES_AMOUNT
from ONLINE_SALE
union
SELECT SALES_DATE,  PRODUCT_ID, null USER_ID,   SALES_AMOUNT
from OFFLINE_SALE)
where to_char(SALES_DATE, 'yyyymm') = 202203
order by SALES_DATE, PRODUCT_ID, USER_ID