Simple PHP MySQL wrapper

db.php

<?php
/*
  This is a simple automagic MySQL wrapper which provides basic protection from SQL injections.
  Usage (after you change database parameters on line 19):
       require_once("db.php"); //in whichever script you want to run SQL code
       ...
       $result = execute_sql("SELECT userId, userName, userAvatar FROM users WHERE username = ? AND email = ?", [$username, $email]);
       foreach($result as $row)
           echo $row["userId"].";".$row["userAvatar"];
           
  This will prepare connection, prepare statement, check if variables are of right type (and/or do casting etc).
  No further code is necessary.

  If query is INSERT/UPDATE/DELETE returned result will be number of affected fields.
*/
$conn = null;

function init_sql()
{
    global $conn;
    $host = "localhost";
    $db = "DATABASENAME";

    $username = "root";
    $password = "";

    try
    {
        $pdo_options[PDO::ATTR_ERRMODE] = PDO::ERRMODE_EXCEPTION;
        $conn = new PDO("mysql:host=$host;dbname=$db", $username, $password, $pdo_options);
    }
    catch(PDOException $e)
    {
        die("Database connection failed!");
    }
}

function execute_sql($sql, $params = [])
{
    global $conn;

    if ($conn == null) init_sql();
    try
    {
        $stmt = $conn->prepare($sql);
        $stmt->execute($params);

        $data = array();

        if ($stmt->columnCount() == 0) //INSERT / UPDATE
            return $stmt->rowCount();

        while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) $data[] = $row;

        return $data;
    }
    catch(Exception $e)
    {
        die("Something died! Error is: $e");
    }
}
?>