Help with PDO (PREPARE)

Question

Hello. I am trying to make a CRUD using PHP OO.

But when I run, I have an error in the preparation of the PDO class.

I have only the bank registration code and the bank connection code for now:

Banco.php

<?php

class Banco{

private $host = 'localhost', $usuario = 'root', $senha = '', $nomeBanco = 'rbtech', $conexao = null;

public function __construct(){
    $this->conecta();   // Chama metodo para conexao
}   //  Fim construct

public function __destruct() {
    if($this->conexao != null){
        $this->conexao = null;
    }   //  Fim destruct
}

    public function conecta(){
        try{
            $this->conexao = new PDO('mysql:host=' . $this->host . ';dbname=' . $this->nomeBanco, $this->usuario, $this->senha);
        } catch (PDOException $e) {
            die('Erro ao conectar com o banco' . $e->getMessage());
        }
    }   //  Fim conecta
}

Register.php

<?php

require_once '../Lib/Banco.php';

class Cadastro extends Banco{

// Porpriedades
public $nome, $sobrenome, $idade;

public function cadastrar(){
    if($_POST){ //  Verifica se é POST
        $pdo = parent::__construct();   //  Chama o construtor da classe Banco
        $sql = "INSERT INTO clientes (nome, sobrenome, idade) VALUES(:nome, :sobrenome, :idade)";   // Query INSERT
        $stmt = $pdo->prepare($sql);
        $stmt->bindParam(':nome', $nome);
        $stmt->bindParam(':sobrenome', $sobrenome);
        $stmt->bindParam(':idade', $idade);

        if($stmt->execute()){
            header('Location: ../index.php');
        }else{
            echo 'Erro ao cadastrar. ';
            print_r($stmt->errorInfo());
        }
    }
}   //  Fim cadastrar
}

$cad = new Cadastro();
$cad->nome = $_POST['nome'];
$cad->sobrenome = $_POST['sobre'];
$cad->idade = $_POST['idade'];
$cad->cadastrar();
var_dump($cad);

I’m starting my studies in Object Orientation with PHP, so this way of receiving form data with object orientation may not be the best way to do it, but a beginner in studies like me, that’s what I was able to develop. And as I said, the code when executed is error in prepare...

Fatal error: Call to a Member Function prepare() on null

Could someone help me with this problem?

And I accept suggestions on how to better receive data from an object-oriented form.

Grateful!

Answer 1

In your example in your Bank class you need a Return in the constructor where you call the $this->connect() method and also a Return in the $this->connect() variable where you connect to the bank, I made the changes where you need to:

private $host = 'localhost', $usuario = 'root', $senha = '', $nomeBanco = 'rbtech', $conexao = null;

public function __construct(){
    return $this->conecta();   // Chama metodo para conexao
}   //  Fim construct

public function __destruct() {
    if($this->conexao != null){
        $this->conexao = null;
    }   //  Fim destruct
}

public function conecta(){
    try{
        return $this->conexao = new PDO('mysql:host=' . $this->host . ';dbname=' . $this->nomeBanco, $this->usuario, $this->senha);
    } catch (PDOException $e) {
        die('Erro ao conectar com o banco' . $e->getMessage());
    }
}   //  Fim conecta

Also edit the variables that you are feeding the bindParam, this way:

 $stmt->bindParam(':nome', $nome);
 $stmt->bindParam(':sobrenome', $sobrenome);
 $stmt->bindParam(':idade', $idade);

But you must edit to:

$stmt->bindParam(':nome', $this->nome);
$stmt->bindParam(':sobrenome', $this->sobrenome);
$stmt->bindParam(':idade', $this->idade);

For you are feeding these variables out of the method.