How do I select and match from multiple tables? - php

Question

This is my table layout:
-- Table structure for table `areas`
CREATE TABLE IF NOT EXISTS `areas` (
`ID` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
`user_id` bigint(20) unsigned NOT NULL,
`country` varchar(20) NOT NULL,
`city` varchar(20) NOT NULL,
PRIMARY KEY (`ID`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;
-- Table structure for table `matches`
CREATE TABLE IF NOT EXISTS `matches` (
`ID` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
`user_id` bigint(20) unsigned NOT NULL,
`view_id` bigint(20) unsigned NOT NULL,
`status` enum('h','n') NOT NULL,
`exp_date` date NOT NULL,
PRIMARY KEY (`ID`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;
-- Table structure for table `users`
CREATE TABLE IF NOT EXISTS `users` (
`ID` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
`limit_age` varchar(5) NOT NULL DEFAULT '18:30',
`limit_gender` varchar(2) DEFAULT NULL,
`notifications` int(11) NOT NULL DEFAULT '0',
`name` varchar(30) NOT NULL,
`email` varchar(40) NOT NULL,
`image_big` varchar(120) NOT NULL,
`image_small` varchar(120) NOT NULL,
`crop_data` int(11) DEFAULT NULL,
`visible` tinyint(1) NOT NULL DEFAULT '0',
`age` int(11) DEFAULT NULL,
`registered_at` datetime NOT NULL,
`views` bigint(20) unsigned NOT NULL DEFAULT '0',
`hots` bigint(20) unsigned NOT NULL DEFAULT '0',
PRIMARY KEY (`ID`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=15 ;
I will try to explain this better:
I have a given ID.
I would like to select one entry from users which is not the ID i have given
AND which user_id does not exist in matches
AND has visible = 1
AND where any country + city matches the given users country + city
Is this the correct way to do it (12 is an example of an given ID):
SELECT *
FROM users a
INNER JOIN areas ON areas.user_id = a.id
WHERE a.id NOT IN (SELECT user_id FROM matches)
AND NOT a.id = '12'
AND a.limit_age = '18:30'
AND a.visible = '1'
AND areas.country = 'sverige'
AND areas.city = 'gbg'
Sorry for the confusion :)

Answer 1

Ok, I'll make an attempt at this:
SELECT *
FROM users a
INNER JOIN areas ON areas.user_id = a.id
WHERE a.id NOT IN (SELECT user_id FROM matches)
AND a.visible = '1'
AND a.limit_age = '18:30'
AND a.limit_gender = 'f'
AND areas.country = ?
AND areas.city = ?;
This is SELECTing from "users", and returning a result only if that user also has an entry in the "areas" table. The first item in the WHERE clause ensures that a row will not be returned if the users.id (a.id) is found in the user_id field on the "matches" table. Next, I added checks for visible = 1, limit_age, and limit_gender as specified in his attempt. Finally, I left country and city parameterized so that they can be added as parameters in the php code. If anything that should give you a starting point.