PHP not writing to first SQL field - php

Question

Thank you guys, worked it out, turns out it was in the js a word wasn't spelled correctly, always something simple
This is my script to write data to my database on my local server, it currently only writes to 2 fields, not the alias one, have I done anything wrong? I've triple checked the names in both the html form and the database field.
<?php
// 1. Create connection to database
mysql_connect('localhost','root','') or die('Could not connect to mysql: <hr>'.mysql_error());
// 2. Select database
mysql_select_db("trialdb") or die('Could not connect to database:<hr>'.mysql_error());
// 3. Assign variables (after connection as required by escape string)
$alias = $_POST['alias'];
$name = $_POST['name'];
$email = $_POST['email'];
// 4. Insert data into table
mysql_query("INSERT INTO user_data (alias, name, email) VALUES ('$alias', '$name', '$email')");
Echo 'Your information has been successfully added to the database.';
print_r($_POST);
mysql_close()
?>

Answer 1

First of all you should always check if the POST variables are being sent correctly:
if (
!isset($_POST['alias']) or
!isset($_POST['name']) or
!isset($_POST['email'])
) // something is wrong
Second, you don't want to inject user input directly into the sql query. You should perform some escaping first (or even better replace the mysql_* deprecated drivers with PDO or mysqli and just use prepared statements):
$alias = mysql_real_escape_string($_POST['alias']);
$name = mysql_real_escape_string($_POST['name']);
$email = mysql_real_escape_string($_POST['email']);
Third, you may want to check if the query performed correctly before printing a success message:
$res = mysql_query("INSERT INTO user_data (alias, name, email) VALUES ('$alias', '$name', '$email')");
echo ($res)
? 'Your information has been successfully added to the database.'
: 'Your information couldn't be added to the database';

Answer 2

you can try
<?php
$conn = mysql_connect('localhost','root','') or die('Could not connect to mysql: '.mysql_error());
mysql_select_db("trialdb", $conn) or die('Could not connect to database:'.mysql_error());
$alias = $_POST['alias'];
$name = $_POST['name'];
$email = $_POST['email'];
mysql_query("INSERT INTO user_data (`alias`, `name`, `email`) VALUES ('$alias', '$name', '$email')", $conn);
echo 'Your information has been successfully added to the database.';
print_r($_POST);
mysql_close();
?>