Property of non-object

[dean7]

Hi all, ive got a problem with this script, well part of it. Its the same script which i needed help with the other day which i manged to sort, but now its came to a bit im not to sure how to fix.

 

$username = $_SESSION['username'];
$location = $fetch_users_data->location;
$carin = mysql_query("SELECT carin FROM users WHERE username = '$username'");// not sure about
$car1 = mysql_query("SELECT * FROM garage WHERE owner = '$username' AND carin = '$carin'");; // not sure about
$car = mysql_fetch_object($car1);

-------------------------------------------------------------------

if ($car->speed <= "39"){ // Line 63
echo ("Your car must be 40mph or faster to win any races.");
}elseif ($car->speed >= "40"){
// Code not needed at the mintue
}

 

Though that little part of the script, its giving me an error which says :

Notice: Trying to get property of non-object in /home/www/*****/****.php on line 63

 

Anyone know why it giving me that error?

 

Thanks for your help.

[mattal999]

$username = $_SESSION['username'];
$location = $fetch_users_data->location;
$carin = mysql_query("SELECT carin FROM users WHERE username = '$username'") or die(mysql_error()); // not sure about
$car1 = mysql_query("SELECT * FROM garage WHERE owner = '$username' AND carin = '$carin'") or die(mysql_error()); // not sure about
if(!$car = mysql_fetch_object($car1)) {
    die("Could not fetch row data - MySQL Error: ".mysql_error());
}

-------------------------------------------------------------------

if ($car->speed <= "39"){ // Line 63
echo ("Your car must be 40mph or faster to win any races.");
}elseif ($car->speed >= "40"){
// Code not needed at the mintue
}

[dean7]

$username = $_SESSION['username'];
$location = $fetch_users_data->location;
$carin = mysql_query("SELECT carin FROM users WHERE username = '$username'") or die(mysql_error()); // not sure about
$car1 = mysql_query("SELECT * FROM garage WHERE owner = '$username' AND carin = '$carin'") or die(mysql_error()); // not sure about
if(!$car = mysql_fetch_object($car1)) {
    die("Could not fetch row data - MySQL Error: ".mysql_error());
}

-------------------------------------------------------------------

if ($car->speed <= "39"){ // Line 63
echo ("Your car must be 40mph or faster to win any races.");
}elseif ($car->speed >= "40"){
// Code not needed at the mintue
}

I done that and it echoed:

 

Could not fetch row data - MySQL Error:

 

But dont know why it carnt fetch the data?

[mattal999]

Ah! I think I've figured it out. Put this just above the mysql_fetch_object() part:

 

echo mysql_num_rows($car1);

[dean7]

Ah! I think I've figured it out. Put this just above the mysql_fetch_object() part:

 

echo mysql_num_rows($car1);

Did that and it echoed 0

[l4nc3r]

Have you tried debugging it?  Lol.

 

Print out the SQL query and put it directly in to MySQL.  See what happens.

 

Print out a mysql_error() right after each mysql_query() function.

 

Also, I see you commented a "not sure about" in your source code.  If you're not sure about something, why not look it up in the manual?

 

Oh, and Google is always your friend: http://www.google.com/search?q=debugging+mysql+php&ie=utf-8&oe=utf-8&aq=t&client=firefox-a&rlz=1R1GGLL_en___US369

[dean7]

Have you tried debugging it?  Lol.

 

Print out the SQL query and put it directly in to MySQL.  See what happens.

 

Print out a mysql_error() right after each mysql_query() function.

 

Also, I see you commented a "not sure about" in your source code.  If you're not sure about something, why not look it up in the manual?

 

Oh, and Google is always your friend: http://www.google.com/search?q=debugging+mysql+php&ie=utf-8&oe=utf-8&aq=t&client=firefox-a&rlz=1R1GGLL_en___US369

Yeah ive tryed de-bugging it, been trying for ages lol. Rather new to php aswell so that dont help. Yeah were I commented "Not sure about" is part which im not sure if it would work.

[Adam]

As I think mattal999 was getting at, you're trying to use mysql_fetch_object() on either an empty resource, or a boolean value (mysql_query() returns false on error). You should validate that rows were actually returned from the SELECT statement with mysql_num_rows, before trying to fetch the data object. For example:

 

if (mysql_num_rows($carl) > 0)
{
    $car = mysql_fetch_object($carl);
}

 

If you still receive some PHP errors for using mysql_num_rows(), you have an error in your syntax.