DB Class

 <?php
class Connection
{
    public $dbhost = "localhost";
    public $dbdriver = "mysql";
    public $dbuser = "root";
    public $dbpass = "usbw";
    public $dbname = "demo";
    public $charset = "utf8mb4";
    public $dbport = "3306";
    public $pdo;
    public $notification;
    public function __construct()
    {
        if (!isset($this->pdo)) {
            try {
                $this->pdo = new PDO($this->dbdriver . ":host=" . $this->dbhost . ";port=" . $this->dbport . ";dbname=" . $this->dbname . ";" . $this->charset, $this->dbuser, $this->dbpass, array(
                    PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
                    PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
                    PDO::ATTR_EMULATE_PREPARES => false,
                    PDO::ATTR_PERSISTENT => true
                ));
                if (!empty($this->pdo)) {
                    $this->notification = "Connected";
                }
            }
            catch (PDOException $e) {
                echo $e->getMessage();
            }
        }
    }


    public function insert($table,$data){

        if (!empty($table) && !empty($data) && is_array($data)) {
            $column = "";
            $value = "";
            $i = 0;
            if (!array_key_exists("created", $data)) {

                $data['created'] = date("Y-m-d H-i-s");
            }

            if (!array_key_exists("modified", $data)) {
                $data['modified'] = date("Y-m-d H-i-s");
            }

            foreach ($data as $key => $value) {
                $pre = ($i > 0)?",":"";
                $column = $pre.$key;
                $value = $pre."'".$value."'";
                $i++;
            }

            $query = "INSERT INTO ".$table." (".$column.") VALUES (".$value.")";
            $insert = $this->pdo->query($query);
            return $insert?$this->pdo->insert_id:false;
        }else{
            return false;
        }
    }

SELECT column1, column2 FROM table_name WHERE condition1 AND condition2 AND condition3   ORDER BY Country ASC, CustomerName DESC LIMIT 0, 10  OFFSET 2;
public function get_row ($table,$condition = array()){

$sql = " SELECT ";
$sql .= array_key_exists("select", $condition)?$condition["select"]:" * ";
$sql .= " FROM ".$table;
if (array_key_exists("where", $condition)) {
    $sql . = " WHERE ";
    $i =0;
foreach ($condition['where'] as $key => $value) {

    $pre = ($i > 0 )?" AND ":"";
    $sql .=$pre.$key." = '".$value."'";
    $i++;
}

}

if (array_key_exists("order_by", $condition)) {
    $sql .= " OREDR BY ".$condition['id'];
}

if (array_key_exists("start", $condition) && array_key_exists("limit", $condition) && array_key_exists("offset", $condition)) {

    $sql .="  LIMIT ".$condition['start'].",".$condition['limit']." OFFSET ".$condition['offset'];
}
elseif (!array_key_exists("start", $condition) && array_key_exists("offset", $condition)) {
        $sql .="  LIMIT ".$condition['limit']." OFFSET ".$condition['offset'];

}
elseif (!array_key_exists("start", $condition) && !array_key_exists("offset", $condition) && array_key_exists("limit", $condition)) {
        $sql .="  LIMIT ".$condition['limit'];

}
// select
$result  = $this->pdo->query($sql);

if (array_key_exists("return_type", $condition) && $condition['return_type'] != "all") {
    switch ($condition['return_type']) {
        case "count":
            $data = $result->num_rows;
            break;
        case "single":
            $data = $result->fetch_assoc();
            break;
        default:
            $data = "";

    }
}

else {
    if ($result->num_rows) > 0 {
        while ($row = $result->fetch_assoc()) {
            $data[]=$row;
        }
    }
}
return !empty($data)?$data:false;
}
$data = [
    'name' => $name,
    'surname' => $surname,
    'sex' => $sex,
];
$stmt = $this->pdo->prepare ("INSERT INTO user (firstname, surname) VALUES (:f-name, :s-name)");
$stmt -> bindParam(':f-name', 'John');
$stmt -> bindParam(':s-name', 'Smith');
$stmt -> execute();
public function insert ($table,$data){
if (!empty($data) && is_array($data)) {

    $columns = "";
    $values = "";
    $i = 0;
    foreach ($data as $key => $value) {
        $pre = ($i > 0)?",":"";
        $columns =$pre.$key;
        $values = $pre."'".":".$value."'";
        $i++;

    }
    $query = " INSERT INTO ".$table." (".$columns.") VALUES (".$values.")";
    $stmt  = $this->pdo->prepare($query);
    $bindcolumn = "";
    $bindvalue = "";
    foreach ($data as $keyb => $valueb) {
        $stmt ->bindParam (':'.$keyb, $valueb);
    }
                return $stmt -> execute();
}
else {
    return false;
}
}

}