奇怪的mySQL连接/写入问题

I don't know if this is relevant in anyway but here goes: I had a script working fine called insert.php and so I then moved onto creating a script that could delete rows. after some testing I noticed the script i was using was connecting to the database but then seemed unable to make any changes. I then ran the MySQL query in phpmyadmin to check it was valid and it worked. I then went back to my insert.php script and that had stopped working too. I then looked at my index.php page and that was inserting the database just fine. Does anyone have the foggiest what might be happening here? I must stress that it 1000% isn't a connection issue

index page which pulls information from the server (this is at the top of the document:

   <?php
$con=mysqli_connect("localhost","root","xxx","xxx");
// Check connection
if (mysqli_connect_errno()) {
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}           
?>      

Connection within insert.php

        $dsn = 'mysql:host=localhost;dbname=GLO12408958DB';
    $username = 'root';
    $password = 'xxx';
    //
    // DB connection was made
    //
    try{
    $pdo = new PDO($dsn, $username, $password,
    array(PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION));
    die(json_encode(array('outcome' => true)));
    }
    catch(PDOException $ex){
    die(json_encode(array('outcome' => false, 'message' => 'Unable to connect')));
    }

connection within delete.php:

<?php
$con=mysqli_connect("localhost","root","xxx","glo12408958db");
// Check connection
 if (mysqli_connect_errno()) {
 echo "Failed to connect to MySQL: " . mysqli_connect_error();
 }  

A few things (the first is probably your problem...):

1. You are using different database names; on most linux / unix systems, mysql identifiers are case sensitive. So GLO12408958DB is not the same as glo12408958db. Unless you are hosting on windows or a mac...
2. You are mixing 2 database api's, PDO and mysqli. You should stick to one although this should work if both are installed;
3. You have a die() statement after you open your PDO connection. Is that just for debugging or is that really there? If it is, remove it.