can't display Id on URL

[kessy cruz]

Good day, I have been on this for day. Please help me out. I will upload some of my files. *A list of category is displayed on d home page. When a user click on any of this category, it displays the list of preachers in that category. I can't get d category id on url. This is the error, Error loading page and localhost/ sitename/?category=. Thanks

<?php

class Preacher{

// The find static method returns an array
// with Product objects from the database.

public static function find($arr){
global $db;

if($arr['id']){
$st = $db->prepare("SELECT * FROM g_preachers WHERE id=:id");
}
if($arr['categoriesID']){
$st = $db->prepare("SELECT g_preachers.name FROM g_preachers INNER JOIN preachcategory ON g_preachers.ID=preachcategory.preachersID INNER JOIN g_categories ON g_categories.ID=preachcategory.categories.ID WHERE g_categories.ID = categoriesID");
}
else{
throw new Exception("Unsupported property!");
}

$st->execute($arr);

return $st->fetchAll(PDO::FETCH_CLASS, "Preacher");
}
}

?> 

[K. Tsang]

Hello there

Have you tried printing out the array $arr? Do the 'id' and 'categoriesID' have values?

Also what is the code look like when user clicks the link? If the link itself has the category ID in the first place, your Preacher class will definitely work.

[kessy cruz]

I have not tried that, but when user click it does not get d Id. Should I upload the codes for you to examine?

[K. Tsang]

Generating parts of the URL (link) dynamically is what you should do (eg the id part). If that page has no access to such info then it surely be blank.