Question

I would like to have the last query (for debugging purposes) from the PDOStatement. But I can’t override the bindParam and bindValue methods. When I tried the code below, I got:

Fatal error: Default value for parameters with a class type hint can only be NULL

Then I replaced the PDO::PARAM_STR to null in the parameter list of bindParam/bindValue, so I got:

Strict Standards: Declaration of DBStatement::bindParam() should be compatible with that of PDOStatement::bindParam()

I then deleted int before the $data_type parameter and set the default value to PDO::PARAM_STR. Then I got:

Strict Standards: Declaration of DBStatement::bindParam() should be compatible with that of PDOStatement::bindParam() in D:\www\pdotest.php on line 73

(interestingly, the bindValue is okay now).

So, what can I do now?

class DBConnection extends PDO
{
    public function __construct($dsn, $username = null, $password = null, $driver_options = array())
    {
        parent::__construct($dsn, $username, $password, $driver_options);

        $this->setAttribute(PDO::ATTR_STATEMENT_CLASS, array('DBStatement', array($this)));
        $this->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    }
}

class DBException extends PDOException
{
    private $query_string;
    private $parameters;

    public function __construct($message = '', $code = 0, $previous = null, $query_string = '', $parameters = array())
    {
        parent::__construct($message, $code, $previous);        

        $this->query_string = $query_string;
        $this->parameters = $parameters;
    }

    public function getQueryString()
    {
        return $this->query_string;
    }   

    public function getParameters()
    {
        return $this->parameters;
    }
}

class DBStatement extends PDOStatement
{
    private $conn;
    private $parameters = array();

    protected function __construct($conn)
    {
        $this->conn = $conn;
    }

    public function bindParam($parameter, &$variable, int $data_type = PDO::PARAM_STR, int $length = null, $driver_options = null)
    {
        $this->parameters[$parameter] = $variable;

        parent::bindParam($parameter, $variable, $data_type, $length, $driver_options);
    }

    public function bindValue($parameter, $value, int $data_type = PDO::PARAM_STR)
    {
        $this->parameters[$parameter] = $value;

        parent::bindValue($parameter, $value, $data_type);
    }

    public function execute($input_parameters = null)
    {
        try
        {
            parent::execute($input_parameters);
        }
        catch (PDOException $e)
        {
            throw new DBException($e->getMessage(), $e->getCode(), $e->getPrevious(), $this->queryString, $this->parameters);
        }
    }
}

$id = 1;

try
{
    $conn = new DBConnection('mysql:host=localhost;dbname=test', 'root', '');
    $stmt = $conn->prepare('select * from foo where id = :id');
    $stmt->bindParam(':id', $id);
    $stmt->execute();
}
catch (DBException $e)
{
    echo "Query string was: ".$e->getQueryString()."\n";
    echo "Parameters was: ".print_r($e->getParameters(), true);
}

I also recieve te following when I throw a DBException (because of $code parameter):

Notice: A non well formed numeric value encountered in D:\www\pdotest.php on line 21

Answer 1

Don’t need to use the “int” type of the $data_type variable, then it works.

public function bindParam($parameter, &$variable, $data_type = PDO::PARAM_STR, $length = null, $driver_options = null)
{
    $this->parameters[$parameter] = $variable;

    parent::bindParam($parameter, $variable, $data_type, $length, $driver_options);
}

public function bindValue($parameter, $value, $data_type = PDO::PARAM_STR)
{
    $this->parameters[$parameter] = $value;

    parent::bindValue($parameter, $value, $data_type);
}