Add a product to the shopping cart - PHP

Hello, I'm trying to make a virtual store in PHP, but whenever I add a product to the shopping cart the program can not access the database and get the product code to display.

<?php
                include("class/conexao.class.php");
                if(count($_SESSION['carrinho']) == 0){
                    echo '<tr><td colspan="5">Não há produto no carrinho</td></tr>';
                }
                else{
                    $conexao = new Conexao();
                    $total = 0;
                    foreach($_SESSION['carrinho'] as $cod => $qtd){
                        $sql    = "SELECT * FROM rec_Produtos WHERE cod='$cod'";
                        $status = sqlsrv_query($conexao, $sql);
                        while ($dados = sqlsrv_fetch_array($status, SQLSRV_FETCH_NUMERIC)){
                            $nome   = $dados[1];
                            $preco = $dados[3];
                            $sub = number_format($preco*$qtd, 2, ',', '.');
                        }
                        $total += $sub;
                        echo '<tr>
                                <td>'.$nome.'</td>
                                <td><input type="text" size="3" name="prod['.$cod.']" value="'.$qtd.'" /></td>
                                <td>R$ '.$preco.'</td>
                                <td>R$ '.$sub.'</td>
                                <td><a href="?acao=del&id='.$cod.'">Remover</a></td>
                            </tr>';
                    }
                    $_SESSION['total'] = number_format($total, 2, ',', '.');
                    echo '<tr>
                            <td colspan="4">Total</td>
                            <td><h5>R$ '.$_SESSION['total'].'</h5></td>
                        </tr>';
                }
?>

This is my Connection class

<?php
    class conexao{
        public $con;
        protected $stmt;
        protected $host = '******';
        protected $database = '******';
        protected $usuario = '******';
        protected $senha = '******';

        public function __construct(){
            $this->con = new PDO("sqlsrv:Server=".$this->host.";Database=".$this->database.";ConnectionPooling=0",$this->usuario,$this->senha);
            if($this->con === false){
                die(print_r(sqlsrv_errors(),true));
            }
            return true;
        }

        private function execSQL($consulta){
            if($consulta === ''){
                return false;
            }
            $stmt = $this->con->prepare($consulta);
            if($stmt){
                $this->stmt=$stmt;
            }
            else{
                $this->sql_error($consulta);
            }
        }

        public function exec($query, $dados) {
            $this->execSQL($query);
            $this->stmt->execute($dados);
        }

        public function select($query, $dados) {
            $this->execSQL($query);
            $this->stmt->execute($dados);
            return $this->stmt->fetchAll();
        }

        public function selectUser($login,$senha){
            $sql = "SELECT * from rec_Cliente where email= ? and senha= ?";
            $this->execSQL($sql);
            $this->stmt->execute(array($login,$senha));
            return $this->stmt->fetchAll();
            //$dados='';
            //while($linha = sqlsrv_fetch_array($this->stmt, SQLSRV_FETCH_ASSOC)){
            //    $dados[] = $linha;
            //}
            //return $dados;
        }

        private function sql_error($sql){
            echo sqlsrv_error($this->con).'<br>';
            die('error: '.$sql);
        }
    }
?>

And this is the connection class for the products

<?php
class conexaoProdutos{
    public $con;
    protected $stmt;
    protected $host = '******';
    protected $database = '******';
    protected $user = '******';
    protected $senha = '******';

    public function __construct(){
        $connectionInfo = array("Database"=>$this->database,"PWD"=>$this->senha,"UID"=>$this->user);
        $this->con = sqlsrv_connect($this->host,$connectionInfo);
        if($this->con === false){
            die(print_r(sqlsrv_errors(),true));
        }
        return true;
    }

    public function __destruct(){
        sqlsrv_close($this->con);
    }

    private function execSQL($consulta){
        if($consulta === ''){
            return false;
        }
        $stmt = sqlsrv_query($this->con,$consulta);
        if($stmt){
            $this->stmt=$stmt;
        }
        else{
            $this->sql_error($consulta);
        }
    }

    public function getTxtDescricao(){
        $sql = "SELECT descricao from rec_Produtos";
        $this->execSQL($sql);
        $dados[]='';
        $i=0;
        while($linha = sqlsrv_fetch_array($this->stmt,SQLSRV_FETCH_NUMERIC)){
            $dados[$i] = $linha[0];
            $i++;
        }
        return $dados;
    }

    public function getProduto(){
        $sql = "SELECT * from rec_Produtos";
        $this->execSQL($sql);
        $dados[]='';
        $i=0;
        while($linha = sqlsrv_fetch_array($this->stmt,SQLSRV_FETCH_NUMERIC)){
            $dados[$i][0] = $linha[0];
            $dados[$i][1] = $linha[1];
            $dados[$i][2] = $linha[2];
            $dados[$i][3] = $linha[3];
            $i++;
        }
        return $dados;
    }

    public function getValor(){
        $sql = "SELECT valor from rec_Produtos";
        $this->execSQL($sql);
        $dados[]='';
        $i=0;
        while($linha = sqlsrv_fetch_array($this->stmt,SQLSRV_FETCH_NUMERIC)){
            $dados[$i] = $linha[0];
            $i++;
        }
        return $dados;
    }

    private function sql_error($sql){
        echo sqlsrv_error($this->con).'<br>';
        die('error: '.$sql);
    }
}
?>

If someone can help me, I appreciate it.