Connect DB with class and Tested if conn exist return exist or create conn

_includes/Database.class.php

+<?php
+
+class Database
+{
+    public static $conn = null;
+
+    public static function getConnection()
+    {
+        if (Database::$conn == null) {
+            $servername = "mysql.selfmade.ninja";
+            $username = "raghav";
+            $password = "R1a2g1h3av";
+            $dbname = "raghav_photogram";
+
+            // Create connection in $conn variable
+            $conn = new mysqli($servername, $username, $password, $dbname);
+            // Check connection
+            if ($conn->connect_error) {
+                die("Connection failed: " . $conn->connect_error); //TODO: we can manage this error with exception handling in future classes... 
+            } else {
+                // Returning the existing data of $conn
+                print("Connected newly");
+                Database::$conn = $conn;
+                return Database::$conn;
+            }
+        } else {
+            // If database already connected it returns the existing value of $conn
+            print("Returned existed connection");
+            return Database::$conn;
+        }
+    }
+}

libs/load.php

@@ -2,6 +2,7 @@
 
 // To include class files automatically
 include_once '_includes/Mic.class.php';
+include_once '_includes/Database.class.php';
 
 function load_template($name)
 {
@@ -22,17 +23,8 @@ function validate_credentials($username, $password)
 // Connecting to database
 function signup($user, $pass, $email, $phone)
 {
-    $servername = "mysql.selfmade.ninja";
-    $username = "raghav";
-    $password = "R1a2g1h3av";
-    $dbname = "raghav_photogram";
-
-    // Create connection
-    $conn = new mysqli($servername, $username, $password, $dbname);
-    // Check connection
-    if ($conn->connect_error) {
-        die("Connection failed: " . $conn->connect_error);
-    }
+    // Store $conn values from class Database
+    $conn = Database::$conn;
 
     $sql = "INSERT INTO `auth` (`username`, `password`, `email`, `phone`, `block`, `active`)
 VALUES ('$user', '$pass', '$email', '$phone', '0', '1');";

test.php

@@ -45,6 +45,10 @@
     $mic1 -> setColorProxy("Red");
     print("From private color: ". $mic1-> getColorProxy());
 
+    // Check whether connection is established or returns existing connection
+    Database::getConnection();
+    Database::getConnection();
+    Database::getConnection();
 
 
     ?>