Foreign Key not linking correctly - php

Question

When registering my first user in table 'users' the id is the same value as user_id in the linking table,1, (language). However, when I register another user (id2 in users) the user_id in language is still 1. See SQL:
CREATE TABLE `language` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`user_id` int(11) NOT NULL,
`native` varchar(30) NOT NULL,
`other` varchar(30) NOT NULL,
`other_list` varchar(9) NOT NULL,
`other_read` varchar(9) NOT NULL,
`other_spokint` varchar(9) NOT NULL,
`other_spokprod` varchar(9) NOT NULL,
`other_writ` varchar(9) NOT NULL,
PRIMARY KEY (`id`),
KEY `user_id` (`user_id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=9 ;
CREATE TABLE IF NOT EXISTS `users` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`md5_id` varchar(200) NOT NULL,
`full_name` tinytext CHARACTER SET latin1 COLLATE latin1_general_ci NOT NULL,
`user_name` varchar(10) NOT NULL,
`user_email` varchar(30) NOT NULL,
`user_level` tinyint(4) NOT NULL DEFAULT '1',
`pwd` varchar(220) NOT NULL,
`nationality` varchar(30) NOT NULL,
`department` varchar(20) NOT NULL,
`birthday` date NOT NULL,
`date` date NOT NULL DEFAULT '0000-00-00',
`users_ip` varchar(200) NOT NULL,
`activation_code` int(10) NOT NULL DEFAULT '0',
`banned` int(1) NOT NULL,
`ckey` varchar(200) NOT NULL,
`ctime` varchar(220) NOT NULL,
`approved` int(1) NOT NULL DEFAULT '1',
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=3 ;
This is my PHP code:
if(empty($_SESSION['$user_id'])) { // user not logged in; redirect to somewhere else }
if (!empty($_POST['doLanguage']) && $_POST['doLanguage'] == 'Submit')
{
$result = mysql_query("SELECT `id` FROM users WHERE `banned` = '0'") or
die (mysql_error());
list($id) = mysql_fetch_row($result);
session_start();
$_SESSION['user_id']= $id;
sql_insert = "INSERT into `language`
(`user_id`,`native`,`other`,`other_list`,`other_read`, `other_spokint`
,`other_spokprod`,`other_writ` )
VALUES
('$id','$native','$other','$other_list','$other_read','$other_spokint',
'$other_spokprod','$other_writ') ";
mysql_query($sql_insert,$link) or die("Insertion Failed:" . mysql_error());
}
header("Location: myaccount.php?id=' . $_SESSION[user_id] .'");
exit();
Would appreciate any help!

Answer 1

I think this is because your initial select query is selecting all users that are not banned
So need to change the query to filter by the new user:
"SELECT `id` FROM users WHERE `banned` = '0' and id=" . $_SESSION['$user_id'];
The reason why the user_id field kept getting populated as 1 was because mysql_fetch_row was getting the first record which was user id 1.
So if you filter it by the new user, mysql_fetch_row should get the id of the new user.
EDIT
I'm just looking at the code again, and it looks like you do not store the user id in php after you insert it, so your user_id for $_SESSION is null.
So my above example will not work. Instead of the above query, use the following function to get the id of your newly created user. You call this function after you run your insert query. That function will get the new of your newly created user.
mysql_insert_id()
http://php.net/manual/en/function.mysql-insert-id.php
EDIT 2
Ok, since mysql_insert_id() didn't work for you, maybe you can try the following. I just changed your select query to order by id desc.
$result = mysql_query("SELECT `id` FROM users WHERE `banned` = '0' order by id desc")
Just a note, this is probably not the best solution. But on a low traffic website it should be fine. To make the query a bit more accurate, you'd want to search for the user id based on a unique field like a username or email. This would make sure you get the correct id back.
EDIT 3
Here is an example of checking for the user's email. This is just the mysql query, you'll have to adjust this for php. Sorry I'm in class right now.
"SELECT `id` FROM users WHERE `banned` = '0' and email='user#email.com' limit 1