Fatal error: Uncaught Error: Using $this when not in object context when I already included the necessary files

Question

<?php
$app = [];
$app['config'] = require 'config.php';
require 'core/helpers.php';
require 'core/util.php';
require 'core/Router.php';
require 'core/Request.php';
require 'core/database/Connection.php';     
require 'core/database/QueryBuilder.php';
require 'core/database/Account.php';
require 'models/Campaign.php';

This is how I code the Connection.php

<?php

class Connection
{
    public static function make($config)
    {
        try {
          return new PDO(
                $config['connection'].';dbname='.$config['name'],
                $config['username'],
                $config['password'],
                $config['options']
            );
        } catch (PDOException $e) {
            die($e->getMessage());
            // exit();
        }
    }
}

and in my QueryBuilder.php or Account.php file, i refer to it like

class QueryBuilder {
    protected $pdo; 

    public function __construct($pdo){
        $this->pdo = $pdo;
    }

this specific query really is the problem here that's why I'm stucked ...

    public static function check_if_the_email_is_currently_registered($pin){
        $sql = "SELECT COUNT(*) FROM users WHERE email = :pin";
        $statement = $this->pdo->prepare($sql);     
        $statement->execute();
        $count =  $statement->fetch(PDO::FETCH_NUM) ; 
        return reset($count); 
    }

I get this error

Fatal error: Uncaught Error: Using $this when not in object context

Can't use `$this` in static function. Use `self::` instead or instantiate the object. — Felippe Duarte, Feb 20 '20 at 18:56
like this one ? ``` $statement = self::pdo->prepare($sql);``` — TheBAST, Feb 20 '20 at 18:58
Instantiate like `new QueryBuilder`. Anyway this seems to be a bad design. `QueryBuilder` class should only build the query, not execute it. — Felippe Duarte, Feb 20 '20 at 19:03
What do you mean by a bad design @FelippeDuarte. The QueryBuilder and Account class would be the class that creates the queries for me . — TheBAST, Feb 21 '20 at 01:35
@TheBAST to do that, make your pdo static first before using self, see docs why. and from there you can use `self::pdo`. — cute_programmer, Feb 21 '20 at 17:03

cute_programmer · Answer 1 · 2020-02-20T19:10:48.313

-1

$this refer to the object instance. when you use static keyword you're referring to the Class level not to the instance level which is why u get the error. Remember you can call your static function without creating the Object. but you're static function use the pdo object which is being created when you create the object QueryBuilder (by using __constructor). hope you figured it out from here.

edited Feb 20 '20 at 19:10

answered Feb 20 '20 at 18:59

cute_programmer

332
3
13

Fatal error: Uncaught Error: Using $this when not in object context when I already included the necessary files

1 Answers1