SQL 코드카타
SELECT person_id,
Concat(name, Concat('(', LEFT(profession, 1), ')')) AS "name"
FROM person
ORDER BY 1 DESC;
SELECT emp_id,
firstname,
lastname,
Max(salary) AS "salary",
department_id
FROM salary
GROUP BY 1,
2,
3
ORDER BY 1;
SELECT artist,
Count(DISTINCT id) AS "occurrences"
FROM spotify
GROUP BY 1
ORDER BY 2 DESC;
문제 링크
이 정도면 굉장히 친절한 문제다..
WITH total
AS (SELECT order_date,
Count(*) AS "cnt"
FROM delivery
GROUP BY 1),
immed
AS (SELECT order_date,
Sum(CASE
WHEN order_date = customer_pref_delivery_date THEN 1
ELSE 0
END) AS "cnt_i"
FROM delivery
GROUP BY 1)
SELECT t.order_date,
Round(100.0 * cnt_i / cnt, 2) AS "immediate_percentage"
FROM total t
LEFT JOIN immed i
ON t.order_date = i.order_date
GROUP BY 1
ORDER BY 1;
SELECT bike_number,
Max(end_time) AS "end_time"
FROM bikes
GROUP BY 1
ORDER BY 2 DESC;
쉬운 문제들이 걸려서 5문제 빠르게 해결!
이제 최종 발표 준비하자🔥