check variables against array

[AdrielGreene]

I'm having some trouble with a registration code check on my website. The members who sign up need to have a unique registration code which is stored in a mysql database. Getting the array looks something like this:

		$q = "SELECT code FROM control";
		$r = mysqli_query ($connect, $q) or trigger_error("Query: $q\n<br />MySQL Error: " . mysqli_error($connect));
		$_control = mysqli_fetch_array ($r, MYSQLI_ASSOC);

Here is where I check against the code:

	if ($_control['code'] ==  $_POST['code']) {
		$reg = mail("myemail@email.net","new member","New member","New member");
	} else {
		echo '<p class="error">Please enter a valid registration code!</p>';
	}

I'm guessing that the POST is only being checked against the first variable in the control array but I could very easily be simply confused. What do you think Dynamic Drive?

[forum_amnesiac]

This is how I would do the query and then the if statatement

$r = mysql_query("SELECT code FROM control") 

You can find the number of rows selected by

$num=mysql_num_rows($r); 

You can then do a while loop

$x=0;
while ($x < $num) {

    if (mysql_result($r,$x,'code') ==  $_POST['code']) {
        $reg = mail("myemail@email.net","new member","New member","New member");
    } else {
        echo '<p class="error">Please enter a valid registration code!</p>';
    }
$x++;
} 

[AdrielGreene]

I tried to adapt my code but nothing I've tried seems to work.

This is what my error checker see's
line 18: mysql_num_rows(): supplied argument is not a valid MySQL result resource

   //create the registration code array
	$q = "SELECT code FROM control";
	$r = mysqli_query ($dbc, $q) or trigger_error("Query: $q\n<br />MySQL Error: " . mysqli_error($dbc));
	$_control = mysqli_fetch_row ($r);
	$regnum = mysql_num_rows($r);


	// Trim all the incoming data:
	$trimmed = array_map('trim', $_POST);

//several lines of code

   // Check for correct registration code:
	$x = 0;
	while ($x <= $regnum) { 
	if ($_control[$x] ==  $trimmed['code']) {$checkreg = 1;} //see if POST data equals a control array value
	$x++;
	}

	if ($checkreg == 1) {
	$reg = 1;
	mail("myself@gmail.com","new practitioner","New Practitioner","New Practitioner");
	} else {
		echo '<p class="error">Please Enter a Valid Registration Code.</p>';
		}

//several lines of code

	if ($reg) { //rest of code

[JasonDFR]

I think the better approach is to ask MySQL to return the row WHERE the unique registration code exists. If it exists in your db, you will get 1 row returned. If it does not exist, you will not get 1 row. Run the query after you get the unique code from the user.

$query = "SELECT * FROM `control` WHERE `code`='$code'";

$result = mysqli_query($link  , $query);

if (mysqli_affected_rows($link) != 1) {

    // Unique code does NOT exist
    // Redirect to error page
    exit;

}

// The rest of your code goes here. 

Good luck.