microphp/Core/DatabaseConnection.php

<?php
    include_once "Helpers.php";
    class DatabaseConnection
    {
        public $client = "mysql";
        public $user = "root";
        public $pass = "";
        public $host = "127.0.0.1";
        public $port = 3306;
        public $database = "";
        public $charset = "utf8mb4";
        public $file = "";
        public $connectionString = null;
        public static $db = null;
        public $ready = false;
        public function __construct(
            $client,
            $user,
            $pass,
            $host = "127.0.0.1",
            $port = "3306",
            $database = "",
            $charset = ""
        )
        {
            $this->client = $client;
            $this->user = $user;
            $this->pass = $pass;
            $this->host = $host;
            $this->port = $port;
            $this->database = $database;
            $this->charset = $charset;
        }
        public function connect()
        {
            if($this->db == null)
            {
                $this->db = new PDO(
                    $this->createConnectionString(),
                    $this->user,
                    $this->pass,
                    array(
                        PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
                    )
                );
                $this->ready = true;
            }
        }
        public function assertConnection()
        {
            if($this->db == null)
            {
                $this->connect();
                if($this->ready == false)
                {
                    throw new Exception("Connection not established");
                }
            };
        }
        public function createConnectionString()
        {
            if($this->connectionString)
            {
                return $this->connectionString;
            }else{
                $str = new tstring($this->client);
                return $str
                    ->concat(":", "host=", $this->host, ";")
                    ->concat("port=", $this->port, ";")
                    ->concat("database=", $this->database, ";")
                    ->concat("host=", $this->host, ";");
            }
        }
        public function exec($sql)
        {
            $this->assertConnection();
            $effected = $this->db->exec($sql);
            if($effected === false)
            {
                throw new Exception($this->db->errorInfo());
            }else{
                return $effected;
            }
        }
        public function lastinsertid()
        {
            $this->assertConnection();
            return $this->db->lastinsertid();
        }
        public function prepare($sql, $params = [])
        {
            $this->assertConnection();
            $prepare = $this->db->prepare($sql);
            if($prepare->execute($params))
            {
                return $prepare;
            }else{
                throw new Exception($this->db->errorInfo());
            }
        }
        public function fetch($sql, $params = [])
        {
            $this->assertConnection();
            return $this->prepare($sql, $params)->fetch(PDO::FETCH_ASSOC);
        }
        public function fetchAll($sql, $params = [])
        {
            $this->assertConnection();
            return $this->prepare($sql, $params)->fetchAll(PDO::FETCH_ASSOC);
        }
    };