Fatal error: Call to a member function num_rows() on a non-object

[knowj]

This is a complete n00b question but I cannot figure out what is wrong. As i have a class doing pretty much the same as what is happening in the error that's working :S

Fatal error: Call to a member function num_rows() on a non-object.

class basket
{
private $items;
private $quantity;
private $database;
private $error;

public static $instance;

private function __construct()
	{
		//create an instance of the database class and connect to the database
		$this->database = database::getinstance();
		//load the session items into the property $this->items
		$this->items = $_SESSION['items'];
		//set the standard error
		$this->error = 'Product Does Not Exist!';
	}

public function getinstance()
	{
		if(self::$instance === null)
			{
				$c = __CLASS__;
				self::$instance = new $c;
			}
		return self::$instance;
	}

public function add($id)
	{
		if ($this->items[$id] <= 0)
			{
				$this->items[$id] = 0;
			}
		if (ereg("([A-Z0-9]+)", $id))
			{
				$results = $this->database->query("SELECT * FROM `products` WHERE code='$id'");
				//line 52 - Fatal error: Call to a member function num_rows() on a non-object
				if ($results->num_rows() == 1)
					{
						$this->items[$id]++;
					}
				else
					{
						return $this->error;
					}
			}
		else
			{
				return $this->error;
			}
	}

private function __destruct()
	{
		$_SESSION['items'] = $this->items;
	}

//note: I didn't include all the class as it just hinders the problem

[laserlight]

It sounds like the database connection object was not created.

[knowj]

If the DB object wasn't created surly the $this->database->query() would error first :S

It seems that I was trying to call num_rows as a function rather than a property.\

public function add($id)
		{
			if ($this->items[$id] <= 0)
				{
					$this->items[$id] = 0;
				}
			if (ereg("([A-Z0-9]+)", $id))
				{
					if ($results = $this->database->query("SELECT * FROM `products` WHERE code='$id'"));
						{
							if ($results->num_rows == 1)
								{
									$this->items[$id]++;
									$results->close();
									return 1;
								}
							else
								{
									return $this->error;
								}
						}
				}
			else
				{
					return $this->error;
				}
		}

This seems to work now.

Anyone know what causes these errors:
Warning: Call to private basket::__destruct() from context '' during shutdown ignored in Unknown on line 0

Warning: Call to private database::__destruct() from context '' during shutdown ignored in Unknown on line 0

[NogDog]

I have not seen it explicitly stated anywhere yet, but it appears that the destructor must have public visibility, thus the error since you defined your __destruct() as private.

[knowj]

Sorry I should have updates this when I sorted it.

Your right nogdog destructor's need to be public. The logic in that I cannot understand.

mysqli seems to be pretty poorly documented in some areas as well from the research I have been doing. Some functions sound like there going to be really useful but when you look into them they have no explanation.

[laserlight]

Your right nogdog destructor's need to be public. The logic in that I cannot understand.

If it is non-public, the object cannot be destroyed (unless it is protected and invoked from a derived class scope).