programmers_오프라인_온라인_판매_데이터_통합하기.sql

# programmers 오프라인/온라인 판매 데이터 통합하기

SELECT DATE_FORMAT(SALES_DATE, '%Y-%m-%d') AS SALES_DATE, PRODUCT_ID, USER_ID, SALES_AMOUNT
FROM ONLINE_SALE
WHERE SALES_DATE LIKE '2022-03-%'
UNION
SELECT DATE_FORMAT(SALES_DATE, '%Y-%m-%d') AS SALES_DATE, PRODUCT_ID, NULL AS USER_ID, SALES_AMOUNT
FROM OFFLINE_SALE
WHERE SALES_DATE LIKE '2022-03-%'
ORDER BY SALES_DATE ASC, PRODUCT_ID ASC, USER_ID ASC