Notice: Trying to get property of non-object

[MasterACE14]

Hello,

 

I'm receiving the following error:

Notice: Trying to get property of non-object in C:\wamp\www\log.php on line 17

I'm absolutely stumped as to why I'm getting this error and hope someone can shed some light on the problem...

here's line 17:

$atack = getAtack($_GET['id']);
echo "<h2>".$atack->userID."</h2>"; // line 17

and here's the getAtack(); function:

function getAtack($id)
  {
      $str = "select * from `AtackLog` where  ID='$id' ";
      //echo $str;
      $q = mysql_query($str);
      if (!$q) {
          echo('Query failed: ' . mysql_error());
          return;
      }
      if (!mysql_num_rows($q)) {
          return 0;
      } else {
          
          $st = "";
          $st = mysql_fetch_object($q);
          return $st;
      }
  }

 

appreciate the help.

 

Regards, Ace

[MasterACE14]

another note, I have....

echo $_GET['id'];

at the top of the page and it does return the correct number.

[ChemicalBliss]

Im guessing its to do with your use of upper and lower case column and table names.

I strongly advise to keep Database,Table and Column names all lowercase.

 

-cb-

[Ken2k7]

Wow, what an awful function. This is one reason why Java methods make it mandatory to state what type to return. Your function does one of 3 different things at completion:

 

1. Exits and returns nothing.

2. Return 0

3. Return an object

 

The problem with that is that it is a pain to check. For 1, you have to check if it returns anything. And then check if the value is 0 or not. It's bad. Terrible.

 

So that means, when you run:

$atack = getAtack($_GET['id']);

 

You don't know what you're going to get. So if getAtack() doesn't return the object, $atack->userID would obviously fail because neither the first or second choices are objects and they would not have a userID member.

 

I suggest you change getAtack().

[Daniel0]

I would throw an exception on error, return null when nothing is found and the object when it exists. This way you can do like this:

 

try {
    if ($attack = getAttack($_GET['id'])) {
        echo 'do something here';
    }
    else {
        echo 'not found';
    }
}
catch (Exception $e) {
    echo 'something fucked up: ' . $e->getMessage();
}

 

Also, you need to make sure you protect against SQL injections in getAttack().