alapp87 / echo360-sql-assessment

Echo360 SQL Assessment

SQL problems

Question 1

Given the following table:

track_media

auto_inc	mediaid	modified
1	x	2001-02-01
2	x	2001-01-31
3	y	2001-01-31
4	y	2001-02-01
5	y	2001-01-30
6	z	2001-01-26

Write a SQL query that yields the most recently modified auto_inc value for each mediaid.

SELECT auto_inc
FROM track_media t1
WHERE modified = (
	SELECT MAX(modified)
	FROM track_media t2
	WHERE t1.mediaid = t2.mediaid
);

Returns the below results:

auto_inc
1
4
6

Question 2

Given the tables:

user_sales

userid	saleid
1	1
1	2
1	3
2	3
2	4
3	5
3	6
3	7
4	8

sale_amount

saleid	amount
1	$4.00
2	$3.50
3	$2.00
4	$3.75
5	$5.25
6	$3.00

Write a SQL query that yields the userids that have total sale amounts greater than 4 dollars and less than 6 dollars.

SELECT userid FROM (
	SELECT u1.userid AS userid, SUM(s1.amount) AS total_amount
	FROM user_sales u1
	JOIN sale_amount s1
	ON u1.saleid = s1.saleid
	GROUP BY u1.userid
	HAVING total_amount > 4
	AND total_amount < 6
);

Returns the below results:

userid
2