PHP - Problem With "sort By" Dropdown Menu?

I am trying to replicate a "Sort By" selection exactly like how Freelancer has it here https://www.freelancer.com/search/projects/

Sort by

- Oldest

- Newest

- Lowest Price

- Highest Price

- Lowest Bid

- Highest Bid

So far I was only able to do the sort by oldest and newest. Here is my code. This shows my code for the page to retrieve records and use pagination to split them.

My Tables:

1. Projects (project_id, title, description, min_budget, max_budget, posted_date, expired_date, status)

2. Bids (bid_id, project_id, details, posted_date, b_status)

3. Images (image_id, project_id, user_id, image_path, posted_date)

4. Currency (currency_id, currency_name)

5. Users (user_id, username)

As you can see the setup I have works only for sorting by DESC and ASC, which is used for Oldest and Newest. Now I would like to know how I can do the same thing for lowest price, highest price using the same query. Lowest and Highest Bid have a separate table. i was wondering if that could also be sorted in the same query as well?

<div id="sort-by-wrap">
  <select id="sort-select" onchange="if(this.value != '') document.location = 'explore-projects?p=3&c1=<?php echo $url_c1; ?>&category=<?php echo $url_category; ?>&name=<?php echo $url_name; ?>&sort_by=' + this.value">
    <option value="DESC"<?php if(isset($_GET['sort_by']) && $_GET['sort_by'] == 'DESC') {echo 'selected="selected"';} ?>>Newest</option>
    <option value="ASC"<?php if(isset($_GET['sort_by']) && $_GET['sort_by'] == 'ASC') {echo 'selected="selected"';} ?>>Oldest</option>
  </select>
  <div id="sort-txt">Sort by:</div>
</div>

<?php
$url_category     	= trim(!empty($_GET['category']) ? $_GET['category'] : null);
$url_name     		= trim(!empty($_GET['name']) ? $_GET['name'] : null);
$url_sort_by  		= trim(!empty($_GET['sort_by']) ? $_GET['sort_by'] : null);
$url_c1           	= trim(!empty($_GET['c1']) ? $_GET['c1'] : null);
$url_page_no  		= trim(!empty($_GET['page_no']) ? $_GET['page_no'] : null);
$page_url 		    = basename($_SERVER['REQUEST_URI']);
$get_page_url		= preg_replace('/[?&]page_no=\d+/', '', $page_url);

if(!empty($url_page_no)) {
  $page_no = $url_page_no;
} else {
  $page_no = 1;
}

$total_records_per_page = 10;
$offset 			= ($page_no - 1) * $total_records_per_page;
$previous_page 		= $page_no - 1;
$next_page 			= $page_no + 1;

$count_records = $db->prepare("SELECT COUNT(*) FROM projects WHERE category_id = :category_id AND publish = :publish");
$count_records->bindParam(':category_id', $url_category);
$count_records->bindValue(':publish', 1);
$count_records->execute();
$total_records = $count_records->fetchColumn();

$total_no_of_pages = ceil($total_records / $total_records_per_page);
$second_last       = $total_no_of_pages - 1; // total page minus 1

$find_records = $db->prepare("SELECT images.image_id, currency.currency_name, users.username, users.user_id, projects.* FROM projects
LEFT JOIN images ON projects.project_id = images.project_id
LEFT JOIN currency ON projects.currency_id = currency.currency_id
LEFT JOIN users ON projects.user_id = users.user_id
WHERE projects.category_id = :category_id AND projects.publish = :publish ORDER BY projects.project_id $url_sort_by LIMIT $offset, $total_records_per_page");
$find_records->bindParam(':category_id', $url_category);
$find_records->bindValue(':publish', 1);
$find_records->execute();
$result_records = $find_records->fetchAll(PDO::FETCH_ASSOC);
if(count($result_records) > 0) {
  foreach($result_records as $row) {
    $project_id       =	$row['project_id'];
    $title            =	$row['title'];
    $description      =	$row['description'];
    $min_budget    	  =	$row['min_budget']);
    $max_budget    	  =	$row['max_budget']);
    $posted_date      =	$row['posted_date'];
    $expired_date     =	$row['expired_date'];
    $status           =	$row['status'];

    $image_id    	  =	$row['image_id'];
    $currency_name    =	$row['currency_name'];

    $user_id    	  =	$row['user_id'];
    $username    	  =	$row['username'];
	
    // COUNT TOTAL BIDS FOR EACH PROJECT
    $count_bids = $db->prepare("SELECT COUNT(*) FROM bids WHERE project_id = :project_id");
    $count_bids->bindParam(':project_id', $project_id);
    $count_bids->execute();
    $total_bids = $count_bids->fetchColumn();

    // HTML CODE TO OUTPUT EACH PROJECT RESULT
    include '../snippets/record-box-wrap.php';
  }

} else {

  ?>
  <div id="no-content">
    <span>No projects</span>
  </div>
  <?php

}
?>
<div class="pagination-wrap">
  <div class="inner-pagination">
    <ul>
      <li <?php if($page_no <= 1){ echo "class='disabled'"; } ?>>
        <a <?php if($page_no > 1){ echo "href='$get_page_url&page_no=$previous_page'"; } ?>>Prev</a>
      </li>
      <?php
      if($page_no <= 6)  {

        for($counter = 1; $counter < 6; $counter++) {
          if ($counter == $page_no) {
           echo "<li class='active'><a>$counter</a></li>";
          } else {
             echo "<li><a href='$get_page_url&page_no=$counter'>$counter</a></li>";
          }
        }

      } else {

        for($counter = $total_no_of_pages - 6; $counter <= $total_no_of_pages; $counter++) {
          if($counter == $page_no) {
            echo "<li class='active'><a>$counter</a></li>";
          } else {
             echo "<li><a href='$get_page_url&page_no=$counter'>$counter</a></li>";
          }
        }
      }
      ?>
      <li <?php if($page_no >= $total_no_of_pages){ echo "class='disabled'"; } ?>>
        <a <?php if($page_no < $total_no_of_pages) { echo "href='$get_page_url&page_no=$next_page'"; } ?>>Next</a>
      </li>
      <?php if($page_no < $total_no_of_pages) { echo "<li><a href='$get_page_url&page_no=$total_no_of_pages'>Last ››</a></li>"; } ?>
    </ul>
  </div>
</div>