add Redis for cache and Mysqli for database query

classes/class_db.php

@@ -0,0 +1,94 @@
+<?php
+
+class DB
+{
+    private  DBInterface $driver;
+
+    private static $instance;
+
+    private static array $queries = [];
+
+    private function __construct()
+    {
+
+    }
+
+    private function __clone()
+    {
+
+    }
+
+    public function setDriver(DBInterface $driver)
+    {
+        $this->driver = $driver;
+
+        return $this;
+    }
+
+    public static function getInstance()
+    {
+        if (self::$instance) {
+            return self::$instance;
+        }
+        $instance = new self;
+        $driver = new DBMysqli();
+        $instance->setDriver($driver);
+        return self::$instance = $instance;
+    }
+
+
+    public function connect($host, $username, $password, $database, $port)
+    {
+        return $this->driver->connect($host, $username, $password, $database, $port);
+    }
+
+    public function query(string $sql)
+    {
+        return $this->driver->query($sql);
+    }
+
+    public function error()
+    {
+        return $this->driver->error();
+    }
+
+    public function errno()
+    {
+        return $this->driver->errno();
+    }
+
+    public function numRows($result)
+    {
+        return $this->driver->numRows($result);
+    }
+
+    public function select_db($database)
+    {
+        return $this->driver->selectDb($database);
+    }
+
+    public function fetchAssoc($result)
+    {
+        return $this->driver->fetchAssoc($result);
+    }
+
+    public function fetchRow($result)
+    {
+        return $this->driver->fetchRow($result);
+    }
+
+    public function affectedRows()
+    {
+        return $this->driver->affectedRows();
+    }
+
+    public function escapeString(string $string)
+    {
+        return $this->driver->escapeString($string);
+    }
+
+
+
+
+
+}