fetching data invalid - php

Question

problem i am facing is when i hit http://www.localhost/test1.php?user=10&num=10
irrespective of num=10&user=10. it displays all the data in the database . how to get particular data with respect to num or user for example num=5 or 6?
<?php
/* require the user as the parameter */
if(isset($_GET['user']) && intval($_GET['user'])) {
/* soak in the passed variable or set our own */
$number_of_posts = isset($_GET['num']) ? intval($_GET['num']) : 10; //10 is the default
$format = strtolower($_GET['format']) == 'json' ? 'json' : 'xml'; //xml is the default
$user_id = intval($_GET['user']); //no default
/* connect to the db */
$link = mysql_connect('localhost','username','pwd') or die('Cannot connect to the DB');
mysql_select_db('marketing',$link) or die('Cannot select the DB');
/* grab the posts from the db */
$query = "SELECT * FROM data";
$result = mysql_query($query,$link) or die('Errant query: '.$query);
/* create one master array of the records */
$posts = array();
if(mysql_num_rows($result)) {
while($post = mysql_fetch_assoc($result)) {
$posts[] = array('post'=>$post);
}
}
/* output in necessary format */
if($format == 'json') {
header('Content-type: application/json');
echo json_encode(array('posts'=>$posts));
}
else {
header('Content-type: text/xml');
echo '<posts>';
foreach($posts as $index => $post) {
if(is_array($post)) {
foreach($post as $key => $value) {
echo '<',$key,'>';
if(is_array($value)) {
foreach($value as $tag => $val) {
echo '<',$tag,'>',htmlentities($val),'</',$tag,'>';
}
}
echo '</',$key,'>';
}
}
}
echo '</posts>';
}
/* disconnect from the db */
#mysql_close($link);
}
?>

Answer 1

In order to have sum of 2 columns saved into the third one automatically you have 2 options:
1. save directly from the code
2. create a trigger.
If a trigger is what you want - here is the trigger
CREATE TRIGGER ins_sum BEFORE INSERT ON user
FOR EACH ROW SET NEW.s3 = NEW.s1+NEW.s2;
Reference to detailed explanation:
https://dev.mysql.com/doc/refman/5.5/en/trigger-syntax.html
And from the code:
INSERT INTO users (s1,s2,s3) values (val1, val2, val1+val2)
Of course here you should change the val1 and val2 to your actual values.