hello im new and need some help :(

[jmelwak]

hi all my name is john,
i have been doing html and flash for years now and want to get into the php and mysql side. I actually am waiting for my PHP book to arrive from sitepoint but i thought i would just jump in to try some things. I love the features it can add to your site. i am just starting out and have a database to display my data in rows and 4 columns. i got this code below and keep getting an error
Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /hsphere/local/home/jmelwak/themusclecar.com/browse.php on line 40
can someone help me ? here is the code

<?php
//set the number of columns
$columns = 4;

mysql_connect('myhost,'myusername','mypassword');
mysql_select_db('mydatabase');
$query = "SELECT cartext FROM cars ORDER BY cars";
$result = mysql_query($query);

//we add this line because we need to know the number of rows
$num_rows = mysql_num_rows($result);
echo "<TABLE BORDER=\"0\">\n";

//changed this to a for loop so we can use the number of rows
for($i = 0; $i < $num_rows; $i++) {
$row = mysql_fetch_array($result);
if($i % $columns == 0) {
//if there is no remainder, we want to start a new row
echo "<TR>\n";
}
echo "<TD>" . $row['stuff'] . "</TD>\n";
if(($i % $columns) == ($columns - 1) || ($i + 1) == $num_rows) {
//if there is a remainder of 1, end the row
//or if there is nothing left in our result set, end the row
echo "</TR>\n";
}
}
echo "</TABLE>\n";
?>

[clamcrusher]

familiarize yourself with this function:
mysql_error()

see the manual for more info/usage examples. php.net/mysql_error
that should help you identify your problem.

[jmelwak]

ok thanks

[webnoob]

$result = mysql_query($query) or die (mysql_error()); 

will explain the error in more detail, but generally it means that the connection to the databse hasnt gone through properly and therefore the function you are calling is not valid. Make sure that your details are correct for connecting to the DB.

[jmelwak]

Originally Posted by webnoob

$result = mysql_query($query) or die (mysql_error()); 

will explain the error in more detail, but generally it means that the connection to the databse hasnt gone through properly and therefore the function you are calling is not valid. Make sure that your details are correct for connecting to the DB.

ohhhh, ok that helps me, i verified everything, im just lost here im now getting an error of Unknown column 'cars' in 'order clause', then when i change that 'cars' to 'cartext' it shows up no errors but blank, nothing?

[jmelwak]

problem solved, thanks for all your help