POST request in swift posting nothing - php

Question

I have got a VC of an app that gets all the variables needed and should pass them through a POST request to a php file, where they are stored and sent to a database. The problem comes when the variables are not set in the database (I believe the connection is well done). The php file is working fine with an Android app that does the same (so the variables are well stored using the Android app).
I would be grateful if you could give me some help.
Swift
#IBAction func modPres(_ sender: AnyObject) {
let postDataURL = "https://www.juankarfollador.com/login_app.php"
let url: NSURL = NSURL(string: postDataURL)!
let request: NSMutableURLRequest = NSMutableURLRequest(url:url as URL)
request.httpMethod = "POST"
request.httpBody = user.data(using: String.Encoding.utf8)
request.httpBody = l_origen.data(using: String.Encoding.utf8)
request.httpBody = l_destino.data(using: String.Encoding.utf8)
request.httpBody = num_pal.data(using: String.Encoding.utf8)
request.httpBody = String(precio).data(using: String.Encoding.utf8)
request.httpBody = texto.data(using: String.Encoding.utf8)
NSURLConnection.sendAsynchronousRequest(request as URLRequest, queue: OperationQueue.main)
{
(response, data, error) in
print(response!)
if let httpResponse = response as? HTTPURLResponse {
let statusCode = httpResponse.statusCode
if statusCode==200 {
print("Connection Successful")
} else {
print("Connection Failed (!200)")
}
}
}
}
Php
$precio = $_POST['precio'];
$texto = $_POST['texto'];
$user = $_POST['user'];
$l_origen = $_POST['l_origen'];
$l_destino = $_POST['l_destino'];
$num_pal = $_POST['num_pal'];
$modificar = $_POST['modificar'];
define('HOST','***');
define('USER','***');
define('PASS','***');
define('DB','***');
$con = mysqli_connect(HOST,USER,PASS,DB) or die('Unable to Connect');
mysqli_set_charset( $con, 'utf8');
//Cliente
$sql = "UPDATE users SET precio='$precio', text_cli='$texto', l_origen='$l_origen', l_destino='$l_destino', num_pal='$num_pal' WHERE username='$user' AND text_cli=''";
mysqli_query($con,$sql);
The console prints "Connection Successful", and this is why I think the connection is well done (I am not sure though, as I am pretty new to Swift)

Answer 1

You are overriding the httpBody of your request over and over.
On top of that you are not passing the keys matching the values of your post variables.
You need something along these lines:
let paramString = "precio=\(precio)&texto=\(texto)&user=\(user)&l_origen=\(l_origen)&l_destino=\(l_destino)&num_pal=\(l_destino)&modificar=\(modificar)"
request.httpMethod = "POST"
request.HTTPBody = paramString.dataUsingEncoding(NSUTF8StringEncoding)
In your PHP I don't see a validation, if you don't have it then you should really add it because it interacts with your db.
Not to mention that you are exposed to SQL injections.