My love for php

<?php

$servername = "xxxx";
$username = "xxxx";
$password = "xxxx";
$dbname = "xxxx";

$conn = new mysqli($servername, $username, $password, $dbname);

if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}


function verifyCredentials($conn, $username, $password){
    $pstm = $conn->prepare("SELECT * FROM xxxx WHERE xxxx =? AND xxxx =?");
    $pstm->bind_param("ss", $username, $password);
    $pstm->execute();
    $pstm->store_result();
    if ($pstm->num_rows > 0) {
        echo 'Credentials correct';
        } else {
        echo 'Credentials incorrect';
    }
    $pstm->close();
}

function incrementValue($conn, $username, $password) {
    $pstm = $conn->prepare("SELECT xxxx FROM xxxx WHERE xxxx =? AND xxxx =?");
    $pstm->bind_param("ss", $username, $password);
    $pstm->execute();
    $result = $pstm->get_result();
    while ($row = $result->fetch_object()) {
        $value = $row->aAttribute + 1; //Specify the attribute that you want to be incremented
        echo $value;
        $pstm = $conn->prepare("UPDATE xxxx SET xxxx = ? WHERE xxxx = ?");
        $pstm->bind_param("is", $value, $username);
        $pstm->execute();
    }
    $pstm->close();
}

function fetchValue($conn, $value, $target) {
    $pstm = $conn->prepare("SELECT ".$target." FROM xxxx WHERE xxxx = ?");
    $pstm->bind_param("s", $value);
    $pstm->execute();
    $result = $pstm->get_result();

    while ($row = $result->fetch_object()) {
        echo $row->$target;
    }
    $pstm->close();
}

function appendToString($value) {
    return $value." a string";
 }

//incrementValue($conn, "xxxx", "xxxx");
//fetchValue($conn, "xxxx", "xxxx");
//verifyCredentials($conn, "xxxx", "xxxx");
//echo appendToString("hello world");


$conn->close();


?>