use study_exam2
SELECT * FROM sale
SELECT prod_code
ㅊ
FROM sale
WHERE sale_ymd LIKE '200801%'
GROUP BY prod_code
SELECT prod_code , CASE WHEN SUM(sale_qty) <= 10 THEN '적음' -- CASE문은 줄일수 있다
ELSE CASE WHEN SUM(sale_qty) <= 20 THEN '보통' --2개안쓰고 줄일수 있다
ELSE '많음' END
END
FROM sale
WHERE sale_ymd LIKE '200801%'
GROUP BY prod_code
SELECT prod_code , CASE WHEN SUM(sale_qty) <= 10 THEN '적음' -- CASE문을 중복안하고 쓸수있다
WHEN (SUM(sale_qty) > 10 AND SUM(sale_qty) <= 20) THEN '보통'
ELSE '많음' END
FROM sale
WHERE sale_ymd LIKE '200801%'
GROUP BY prod_code