#1

SELECT
	albumid,
	COUNT(trackid)
FROM
	tracks
GROUP BY
	albumid;

#2

SELECT
	albumid,
	COUNT(trackid)
FROM
	tracks
GROUP BY
	albumid
HAVING albumid = 1;

#3

SELECT
	albumid,
	COUNT(trackid)
FROM
	tracks
GROUP BY
	albumid
HAVING count(albumid) BETWEEN 18 AND 20
ORDER BY albumid;

#4

SELECT
	tracks.albumid,
	title,
	sum(Milliseconds) AS length
FROM
	tracks
INNER JOIN albums ON albums.AlbumId = tracks.AlbumId
GROUP BY
	tracks.albumid
HAVING
	length > 60000000;

albums artists customers employees genres invoice_items invoices media_types playlist_track playlists tracks