Question

I am having trouble selecting first photo (thumb_filename) and date added (date_added) on every unique article. Every unique article is a gallery for itself.

I am beginner in MySQL, so hope someone could help.

CREATE TABLE IF NOT EXISTS `photographs` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `article_id` int(11) NOT NULL,
  `thumb_filename` varchar(255) NOT NULL,
  `full_filename` varchar(255) NOT NULL,
  `date_added` datetime NOT NULL,
  PRIMARY KEY (`id`),
  KEY `article_id` (`article_id`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 AUTO_INCREMENT=31 ;

I know to use SELECT thumb_filename, date_added FROM photographs and than to filter this out using PHP. I don’t know how to set condition for unique article_id…

Answer 1

Untested of course, but this may do the job for you. This isn’t the only way to do it, but it is a straightforward way. It pulls photograph ids for the earliest date_added of each article_id and then uses those to retrieve the filename.

SELECT 
  thumb_filename,
  date_added
FROM photographs
WHERE id IN (SELECT id FROM photographs GROUP BY article_id HAVING MIN(date_added))