Is there a reason my execute command for PDO isn't working?

I am just beginning to learn about PHP OOP through videos on youtube and I am following along in building a website application.

I have to connect to the SQL database using PDO as the guy explained. I followed everything he did but my execution part for the PDO is not working and I don't know what is wrong with it. The code is below. it does not bring up any errors it just doesn't bring back any data from the database. I put some echos in between the function to find out how far the code is going and that is how I found out that it prepares the query but never executes it. Please help me figure this out. Thank you.

class Database{
private function connect()
{
    $string = DBDRIVER . ":host =" .DBHOST.";dbname =".DBNAME;
    if ($conn = new PDO($string, DBUSER, DBPASS)) {
        return $conn;
    } else {
        die("Could not connect to database");
    }
}

The code above is the connection to the database. it is working correctly as far as I can tell.

The code below is supposed to return the data from the database back to be displayed using a view.php file

public function query($query, $data = array(), $data_type = "object")
{

    $con = $this->connect();
    $stm = $con->prepare($query);
    print_r($stm);

    if ($stm) {
        $check = $stm->execute($data); //right here is where I concluded that the code stops
        print_r($check);//does not print anything
        if ($check) {
            if ($data_type == "object") {
                $data = $stm->fetchAll(PDO::FETCH_OBJ);
            } else {
                $data = $stm->fetchAll(PDO::FETCH_ASSOC);
            }

            if (is_array($data) && count($data) > 0) {
                return $data;
            }
        }
    }
    return false;
}

below is the part written in the controller to assign the query to the database to execute.

function index(){

        $db = new Database();
        
        $data = $db->query("select * from users");
        if($data){echo $data;} //echos nothing because $data is empty
        $this -> view('home', ['rows' => $data]);
    }

by Ezra in StackOverflow on June 05, 2022.

Answer

i have tested your code the error occurs because u have a space between the dbname and the =. A semicolon after the DBNAME is also missing (it is not needed).

class Database{
private function connect()
{
    $string = DBDRIVER . ":host=" .DBHOST.";dbname=".DBNAME.";";
    if ($conn = new PDO($string, DBUSER, DBPASS)) {
        return $conn;
    } else {
        die("Could not connect to database");
    }
}

Now it works for me.

i am using this connection class for a long time, maybe you want to use it.

class Connection{

    private const CONNECTION = [
        "Host" => "",
        "User" => "",
        "Password" => "",
        "Databasename" => ""
    ];

    /**
     * Includes the pdo connection.
     * @var \PDO|null
     */
    private \PDO|null $PDO = null;

    /**
     * Includes the already called instance.
     * @var Connection|null
     */
    private static self|null $Connection = null;

    /**
     * Creates the DB connection and sets it to the class.
     * @return void 
     * @throws Exception 
     */
    private function __construct()
    {
        $Connection_str = 'mysql:';
        $Connection_str .= 'host=' . self::CONNECTION["Host"] . ';';
        $Connection_str .= 'dbname=' . self::CONNECTION["Databasename"] . ';';
        $Connection_str .= 'charset=utf8mb4';
        $this->PDO = new \PDO($Connection_str, self::CONNECTION["User"], self::CONNECTION["Password"]);
        $this->PDO->setAttribute(\PDO::ATTR_ERRMODE, \PDO::ERRMODE_EXCEPTION);
        $this->PDO->setAttribute(\PDO::ATTR_EMULATE_PREPARES, false);
        $this->PDO->setAttribute(\PDO::ATTR_DEFAULT_FETCH_MODE, \PDO::FETCH_ASSOC);
    }

    /**
     * Returns the static DB connection instance.
     * @return Connection 
     * @throws Exception 
     */
    public static function get(): Connection
    {
        return !isset(self::$Connection) ? self::$Connection = new self : self::$Connection;
    }

    /**
     * Returns the PDO instance.
     * @return PDO 
     * @throws Exception 
     */
    public function getPDO(): \PDO
    {
        return $this->PDO;
    }
}

You can use the connection class using the following code:

$SQLString = "select * from users";
$Data = [

];
$Query = Connection::get()->getPDO()->prepare($SQLString);
$Query->execute($Data);
$Data = $Query->fetchAll();

by Jonathan Wyrwich on June 05, 2022.