PHP MySQLi not inserting into tables

Question

I've looked at some of the other similar questions, but still can't seem to get it working. FWIW, I am not getting any specific error message.

<?php

// Create connection
$con=mysqli_connect("localhost","username","password");
mysqli_select_db($con, "database");
//let's start our session, so we have access to stored data
session_start();

$class = mysqli_real_escape_string($_SESSION['exclass']);
$fullname = mysqli_real_escape_string($_SESSION['fullname']);
$june = mysqli_real_escape_string($_SESSION['June']);
$july = mysqli_real_escape_string($_SESSION['July']);
$email = mysqli_real_escape_string($_POST['email']);
$phone = mysqli_real_escape_string($_POST['phone']);

//let's create the query
$insert_query = "INSERT INTO Responses (class,fullname,June,July,email,phone) VALUES ('$class','$fullname',$june,$july,'$email','$phone',)";

//let's run the query
$result = mysqli_query($con,$insert_query);

if($result){
    echo "Your response has been recorded. Thank you!";

}else{

    printf("Insert failed: %s\n", mysqli_error());
}
?>

Answer 1

MySQL does not support trailing comma notation.

Thus, replace:

,'$phone',)

with

,'$phone')

Also, add a fallback condition to see the error output buffer:

mysqli_query($con, $insert_query) or die(mysqli_error($con));

Answer 2

"INSERT INTO Responses (class,fullname,June,July,email,phone) VALUES    ('$class','$fullname',$june,$july,'$email','$phone',<--- LOOK AT THIS COMMA)

This will more than likely explain the failure to insert into the database. Remove the comma from the SQL string, and it will parse correctly.