Error in Function connection class code

Question

I’m in trouble, look at the code I made:

<?php
class banco {
   public function __construct() {
 
        $banco_hostremoto = "127.0.0.1";
        $banco_hostname = "localhost";
        $banco_usuario="root";
        $banco_passwd="";
        $banco_nome="flptrevisan";
       
        $conn = mysql_connect($banco_hostname,$banco_usuario,$banco_passwd);
        if (!mysql_ping($conn)) {   $FORADOAR = TRUE;   }
        else if (mysql_ping($conn)) {
            $FORADOAR = FALSE;
            $conexao = new mysqli($banco_hostname,$banco_usuario,$banco_passwd,$banco_nome);
        }
       
    }
    public function signIn($email,$senha) {
        $this->conexao->query("SELECT * FROM usuarios WHERE email = '$email' AND senha = '$senha'");
        if ($sql->num_rows==1){
                while($linha =  $sql->fetch_array()) {
                        $usuario = $linha['nome'];
                        $acessos = $linha['acessos']+1;
                }
                $ip=$_SERVER["REMOTE_ADDR"];
                $sql = $conexao->prepare("UPDATE usuarios SET acessos = ?, ip = ? WHERE email = ?");
                $sql->bind_param('iss',$acessos,$ip,$email);
                $sql->execute();
                $_SESSION["autenticado"]=$email;
                $_SESSION["usuario"]=$usuario;
                header('location:index.php');
        }
        else {
                echo '<div class="alertaIndexMSG">O usuário ou senha inserido é inválido(a)</div>';
        }
    }
 
}

From the following error:

Notice: Undefined Property: bank::$connectionin C: htdocs Netbeansprojects flptrevisan classes conexao.class.php on line 20

Fatal error: Call to a Member Function query() on a non-object in C: htdocs Netbeansprojects flptrevisan classes conexao.class.php on line 20

Line 20 is:

$this->connection->query("SELECT * FROM users WHERE email = '$email' AND password = '$password'");

Answer 1

Properties must be declared in the body of the class in the case $conexao was defined as a local variable of the constructor so soon after its call it lost its value.

Define $conexao as a member of the class so:

class banco {
   private $conexao;
//........

Follow the guidelines of previous question

Just reinforcing a few things:

• Avoid receiving/manipulating super globals such as $_GET, $_POST, $_COOKIE, $_SESSION directly in methods if you need to pass them as a parameter or reassign the value as a return (in the case outside the class/method).

• Methods should do/solve only one part of the job/problem, your constructor is doing two fines besides initializing the variables is checking if the server is online, if you really need it create a new method:

Change:

public function __construct() {
    $conn = mysql_connect($banco_hostname,$banco_usuario,$banco_passwd);
    if (!mysql_ping($conn)) {
        $FORADOAR = TRUE;
    }else if (mysql_ping($conn)){
        $FORADOAR = FALSE;
        $conexao = new  mysqli($banco_hostname,$banco_usuario,$banco_passwd,$banco_nome);
    }

for:

public function servidorOnLine(){
  return $this->conexao->ping();
}

• There is a lostmysql_* there in the constructor forget it, Why should we not use mysql type functions_*?