I cant´t add data to my database - php

Question

Godd night. I have this code for php to add data to my database but i dont get succes.
<?php
require("config.inc.php");
if (!empty($_POST)) {
$user = $_POST['User'];
$mail = $_POST['Mail'];
$token = $_POST['Token'];
$pass = $_POST['Pass'];
$result = mysqli_query($con,"SELECT 1 FROM Proteos where
User='$user'");
$row = mysqli_fetch_array($result);
$data = $row[0];
if($data==0){
echo $data;
echo "Hey, un grato saludo mister ".$user."!\n";
$query = "INSERT INTO Proteos (User, Mail ) VALUES ($user,$mail ) ";
}
mysqli_close($con)
And this is my config.inc
<?php
define('DB_SERVER','mysql.smartfreehosting.net');
define('DB_NAME','u178665800_prote');
define('DB_USER','u178665800_carin');
define('DB_PASS','xxxxxx');
$con = mysql_connect(DB_SERVER,DB_USER,DB_PASS);
mysql_select_db(DB_NAME,$con);
?>

Answer 1

Put your value in single quote And than execute query
$query = "INSERT INTO Proteos (User, Mail ) VALUES ($user,$mail ) ";
to
$query = "INSERT INTO Proteos (User, Mail ) VALUES ('$user','$mail') ";
And after that pass $query to mysqli_query like
mysqli_query($con,$query);

Answer 2

String values have to be passed in quotes. Also execute the query .
To debug use mysqli_error
$query = "INSERT INTO Proteos (User, Mail ) VALUES ('{$user}','{$mail}' ) ";
mysqli_query($con,$query);
or
mysqli_query($conn, $query) or die(mysqli_error($conn));
to connect with mysqli (ref) change in config.inc
$con = mysqli_connect(DB_SERVER,DB_USER,DB_PASS, DB_NAME);

Answer 3

You are inserting VARCHAR (string) data into Database without single quotes.
Data without single quotes is considered as either table/field names or integers or keywords.
Your entered data being none of these is causing errors.
Corrected SQL:
$query = "INSERT INTO Proteos (User, Mail ) VALUES ('$user','$mail') ";

Answer 4

<?php
require("config.inc.php");
if (!empty($_POST)) {
$user = $_POST['User'];
$mail = $_POST['Mail'];
$token = $_POST['Token'];
$pass = $_POST['Pass'];
$result = mysqli_query($con,"SELECT 1 FROM Proteos where
User='$user'");
$row = mysqli_fetch_array($result);
$data = $row[0];
if($data==0){
echo $data;
echo "Hey, un grato saludo mister ".$user."!\n";
mysqli_query($con,"INSERT INTO Proteos (User, Mail ) VALUES ('$user','$mail' ) ") or die(mysqli_error());
}
mysqli_close($con);
check above code, values are insert using 'var' like '$user','$mail'
any error shows in the query helps to find the code or die(mysqli_error())