Why is my database table not updated after this query? - php

Question

I am using a dedicated server through 1 and 1 and the PHP code as below will not insert the data into the database.
All connections to database are correct.
$id = $_REQUEST['id'];
$content = $_REQUEST['content'];
mysql_query("UPDATE `content` SET `content` = '$content' WHERE `id`='$id'");
When I test on my local server all works fine, there is something about the server that will not allow me to upload. I am connecting using a very general method
$connection = mysql_connect("localhost",
"root",
"password");
mysql_select_db("dbname", $connection);

Answer 1

1) Turn on error reporting by putting this on the top of your PHP script:
error_reporting(E_ALL);
2) Run your script. Any errors? If yes, proceed according to the error message you get.
3) Double check that your variables are actually defined (you are getting them from the request, you cannot be sure request actually contains values you are trying to use).
4) Your SQL query is very dangerous. Use mysql_real_escape_string() or prepared statements. Don't put quotes around integer values.
5) Edit your script to look more like this:
error_reporting(E_ALL);
$id = (isset($_REQUEST['id']) && !empty($_REQUEST['id'])) ? $_REQUEST['id'] : NULL;
$content = (isset($_REQUEST['content']) && !empty($_REQUEST['content'])) ? $_REQUEST['content'] : NULL;
try{
if(NULL === $id){
throw new Exception('$id is NULL');
}
if(NULL === $content){
throw new Exception('$content is NULL');
}
$id = mysql_real_escape_string($id);
$content = mysql_real_escape_string($content);
$sql = "UPDATE content SET content = '$content' WHERE id = $id";
// connect to database
// ...
mysql_query($sql);
}catch(Exception $e){
echo '<p style="color: red;">',$e->getMessage(),'</p>';
}

Answer 2

Ddebugging for beginners...
You haven't posted any errors, is error reporting turned off? Debugging is much easier with error reporting turned on.
error_reporting(E_ALL);
We'll also want to see what the actual query we're trying to run in the database. Perhaps the variables haven't been properly escaped (Contains illegal characters).
$query = "UPDATE table SET name='$name' where id='$id'";
echo $query;
mysql_query($query);
My guess is that you have to mysql_real_escape_string(); both variables.
Also you pass $id as a string, it's probably an integer.

Answer 3

You're mishandling transactions.