SELECT(3) | MySQL

SELECT USER_ID, PRODUCT_ID
FROM ONLINE_SALE
GROUP BY USER_ID, PRODUCT_ID
HAVING COUNT(*) >= 2
ORDER BY USER_ID ASC, PRODUCT_ID DESC
;

SELECT A.REST_ID, A.REST_NAME, A.FOOD_TYPE, A.FAVORITES, A.ADDRESS, ROUND(AVG(B.REVIEW_SCORE), 2) AS SCORE
FROM REST_INFO AS A JOIN REST_REVIEW AS B
ON A.REST_ID = B.REST_ID
GROUP BY A.REST_ID
HAVING A.ADDRESS LIKE '서울%'
ORDER BY SCORE DESC, A.FAVORITES DESC
;

(
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
;