Question

I need a little help for one sql query;

here is my basic user database table

CREATE TABLE IF NOT EXISTS `users` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `email` varchar(100) NOT NULL,
  `pass` varchar(255) NOT NULL,
  `fname` varchar(50) NOT NULL,
  `lname` varchar(40) NOT NULL, 
  `network` varchar(10) NOT NULL, 
  PRIMARY KEY (`id`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=27 ;

and here is my basic topics database table

CREATE TABLE IF NOT EXISTS `topics` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `userid` varchar(100) NOT NULL,
  `title` varchar(255) NOT NULL,
  `body` text,
  `tags` varchar(256) NOT NULL,  
  PRIMARY KEY (`id`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=2 ;

What I’m trying to do is;
i.e. list all topics from users who joined “harvard” network

Answer 1

You just need a simple JOIN. Join the tables on the userID (of those who are in "harvard").

SELECT title,body
FROM topics, users
WHERE userid = users.id
AND network = 'harvard'

Or using the JOIN keyword:

SELECT title,body
FROM topics
JOIN users ON userid = users.id
WHERE network = 'harvard'