选择最频繁的5行，并从另一个表中查询数据

Question

Let's say I have 2 tables on my database,

The first one:

TABLE "SONGS"
+----+-------+--------+
| id | title | artist |
+----+-------+--------+
|  1 | song1 |   blah |
|  2 | song2 |   wut? |
|  3 | song3 | random |
+----+-------+--------+

And another one:

TABLE "PLAYS"
+----+---------+--------+
| id | song_id |  time  |
+----+---------+--------+
|  1 |       2 |  13:04 |
|  2 |       1 |  13:07 |
|  3 |       1 |  14:30 |
|  4 |       3 |  14:41 |
|  5 |       2 |  14:59 |
|  6 |       1 |  15:32 |
+----+---------+--------+

I was trying to have my script query out the most frequent song_id from the table plays then join it with the title and artist in the songs table to make the music chart for a radio station, but so far no luck on getting the result.

This is the expected result:

[
    {"song_id": 1, "title": "song1", "artist": "blah", "plays": 3},
    {"song_id": 2, "title": "song2", "artist": "wut?", "plays": 2},
    {"song_id": 3, "title": "song3", "artist": "random", "plays": 1}
]

Thank you in advance.

Answer 1

You can do a regular JOIN between the tables, counting the number of rows per id/artist/title and ordering by that;

SELECT s.id, s.title, s.artist, COUNT(*) plays
FROM songs s
JOIN plays p
  On s.id = p.song_id
GROUP BY s.id, s.title, s.artist
ORDER BY plays DESC

An SQLfiddle to test with .

To just get the play order with just an id, no need to join;

SELECT song_id, COUNT(*) plays
FROM plays p
GROUP BY song_id
ORDER BY plays DESC

Another SQLfiddle .

To just get the top 5 results, a LIMIT 5 can be appended added to either query.