MySql PHP Update Error - php

Question

I've been messing about with this code for a few hours now and can't work out why it's not working. It's a profile update php page that is passed through JQuery and all seems to be fine except for it actually updating into the table. Here is the code I'm using:
session_start();
include("db-connect.php");//Contains $con
$get_user_sql = "SELECT * FROM members WHERE username = '$user_username'";
$get_user_res = mysqli_query($con, $get_user_sql);
while($user = mysqli_fetch_array($get_user_res)){
$user_id = $user['id'];
}
$name = mysqli_real_escape_string($con, $_REQUEST["name"]);
$location = mysqli_real_escape_string($con, $_REQUEST["location"]);
$about = mysqli_real_escape_string($con, $_REQUEST["about"]);
$insert_member_sql = "UPDATE profile_members SET id = '$user_id', names = '$name', location = '$location', about = '$about' WHERE id = '$user_id'";
$insert_member_res = mysqli_query($con, $insert_member_sql) or die(mysqli_error($con));
if(mysqli_affected_rows($con)>0){
echo "1";
}else{
echo "0";
}
All I get as the return value is 0, can anybody spot any potential mistakes? Thanks

Answer 1

To begin with, use
require("db-connect.php");
instead of
include("db-connect.php");
And now, consider using prepared statements, your code is vulnerable to sql injections.
Consider using PDO instead of the mysql syntax, in the long run I find it much better to use and it avoids a lot of non-sense-making problems, you can do it like this (You can keep it in the db-connect file if you want, and even make the database conncetion become global):
// Usage: $db = connectToDatabase($dbHost, $dbName, $dbUsername, $dbPassword);
// Pre: $dbHost is the database hostname,
// $dbName is the name of the database itself,
// $dbUsername is the username to access the database,
// $dbPassword is the password for the user of the database.
// Post: $db is an PDO connection to the database, based on the input parameters.
function connectToDatabase($dbHost, $dbName, $dbUsername, $dbPassword)
{
try
{
return new PDO("mysql:host=$dbHost;dbname=$dbName;charset=UTF-8", $dbUsername, $dbPassword);
}
catch(PDOException $PDOexception)
{
exit("<p>An error ocurred: Can't connect to database. </p><p>More preciesly: ". $PDOexception->getMessage(). "</p>");
}
}
And then init the variables:
$host = 'localhost';
$user = 'root';
$databaseName = 'databaseName';
$pass = '';
Now you can access your database via
$db = connectToDatabase($host, $databaseName, $user, $pass);
Now, here's how you can solve your problem (Using prepared statements, avoiding sql injection):
function userId($db, $user_username)
{
$query = "SELECT * FROM members WHERE username = :username;";
$statement = $db->prepare($query); // Prepare the query.
$statement->execute(array(
':username' => $user_username
));
$result = $statement->fetch(PDO::FETCH_ASSOC);
if($result)
{
return $result['user_id'];
}
return false
}
function updateProfile($db, $userId, $name, $location, $about)
{
$query = "UPDATE profile_members SET name = :name, location = :location, about = :about WHERE id = :userId;";
$statement = $db->prepare($query); // Prepare the query.
$result = $statement->execute(array(
':userId' => $userId,
':name' => $name,
':location' => $location,
':about' => $about
));
if($result)
{
return true;
}
return false
}
$userId = userId($db, $user_username); // Consider if it is not false.
$name = $_REQUEST["name"];
$location = $_REQUEST["location"];
$about = $_REQUEST["about"];
$updated = updateProfile($db, $userId, $name, $location, $about);
You should check the queries though, I fixed them a little bit but not 100% sure if they work.
You can easily make another function which inserts into tha database, instead of updating it, or keeping it in the same function; if you find an existance of the entry, then you insert it, otherwise you update it.