here's the relevant code:

<?php

DEFINE ('DB_USER','root');
DEFINE ('DB_PASSWORD','');
DEFINE ('DB_HOST','localhost');
DEFINE ('DB_NAME','citations');

//create the db connection
$dbc = mysqli_connect ( DB_HOST,
DB_USER,
DB_PASSWORD,
DB_NAME)
OR die ('Could not connect to MySQL');
var_dump($dbc);

echo "<pre>"; print_r($_POST); echo "</pre>";

/////////////////////////////////////////////////////////////

$permitNum = $_POST['permitNum'];
$q = "select count(permitNum) FROM permits"; //just a test query
echo $q; //recommended for testing
$r = mysqli_query($db, $q);
if($r){echo "<h1>query worked</h1>";} //testing
$duplicate_pNum = mysqli_fetch_assoc($r);
print_r($duplicate_pNum); //testing



and here is the relevant output:
$dbc exists
object(mysqli)#1 (0) {
}
Array
(
[permitNum] => 44444
[licensePlateNum] => 44444444
[ownerFirst] => a
[ownerLast] => a
[addPermit] => 1
)
select count(permitNum) FROM permits
Warning: mysqli_query() expects parameter 1 to be mysqli, null given in E:\xampplite\htdocs\WEB250\module5\lab4.php on line 78

Warning: mysqli_fetch_assoc() expects parameter 1 to be mysqli_result, null given in E:\xampplite\htdocs\WEB250\module5\lab4.php on line 80

//////////////////////////////////////////////////

I've looked around, and can't find an answer to this. I implemented some of the recommended tests (dump $dbc, echo query, etc.) but it don't help. someone recommended echoing query cuz they said there was a problem with the query, but I don't think so. There is some problem with the connection identifier. I've attached the whole file, just in case it helps.

THANKS, this problem has stopped me in my tracks.

Hey anonymouse,

Looks like you have your parameters backwards in your query. Should be mysqli_query($q, $db);

Try it out and see if it works. I would recommend using mysqli_select_db() to select your db if you're not using multiple db connections, and then omit the $db param from the mysqli_query().

Also, make sure you're passing $_POST vars or it will break your query. You should add an if/else to make sure.

Hope this helps.
Rich