Question

I have the following structure:

Album

+----------+----------------------+-------------------+-------------------+--------+
| id_album | description          | name              | url               | status |
+----------+----------------------+-------------------+-------------------+--------+
|        1 | el primer album      | primer album      | primer-album      |      1 |
|        2 | El album del viernes | album del viernes | album-del-viernes |      1 |
|        3 | dasdas               | album 3           | album             |      1 |
+----------+----------------------+-------------------+-------------------+--------+

Photo

+----------+-------------+-----------------------------+-------+---------+
| id_photo | description | image           | album | published           |
+----------+-------------+-----------------------------+-------+---------+
|        1 |             | 1_1361894_n.jpg |     1 | 2012-05-24 13:36:36 |
|        2 |             | 1_537885_n.jpg  |     1 | 2012-05-24 13:36:39 |
|        3 |             | 17227078_n.jpg  |     1 | 2012-05-24 13:36:40 |
|        4 |             | _6891390_n.jpg  |     1 | 2012-05-24 13:36:40 |
|        5 |             | 15743568_n.jpg  |     1 | 2012-05-24 13:36:44 |
|        6 |             | -sol.jpg        |     2 | 2012-06-29 09:55:23 |
|        9 |             | fondo2.gif      |     2 | 2012-08-13 16:46:10 |
|        8 |             | barra.gif       |     1 | 2012-07-10 12:13:04 |
+----------+-------------+-----------------+-------+---------------------+

---

Actually, I’m selecting all albums that contains at least one photo:

SELECT a.id_album, a.name, count(p.id_photo) AS photos 
FROM album a
LEFT JOIN photo p ON a.id_album = p.album 
GROUP BY a.id_album 
HAVING photos > 0;

+----------+-------------------+--------+
| id_album | name              | photos |
+----------+-------------------+--------+
|        1 | primer album      |      6 |
|        2 | album del viernes |      2 |
+----------+-------------------+--------+

Everyting goes fine here. But now, I would like to know if is possible to include one
photo for each album into the row. For exaple:

| id_album | name | photos | id_photo | image |

Look above that I have included id_photo and image from photo table. But I don’t know how to trigger a sql to get that result. I apreciate your help.

Answer 1

SELECT a.id_album, a.name, count(p.id_photo) AS photos, p.id_photo, p.image 
FROM album a
LEFT JOIN photo p ON a.id_album = p.album 
GROUP BY a.id_album 
HAVING photos > 0;

Most probably it will take first inserted album’s photo if it has any photo.