Search query

functions.php

<?php

// ---- //
function do_search(){
    global $wpdb;

    if(isset($wpdb)):

        // assign all variables from our get data
        $filter_year = isset($_GET['pub_year']) ? $_GET['pub_year'] : '';
        $filter_month = isset($_GET['pub_month']) ? $_GET['pub_month'] : '';
        $filter_keyword = isset($_GET['keyword']) ? $_GET['keyword'] : '';

        // clear existing queries
        $wpdb->flush(); 

        $select = "SELECT * FROM wp_posts";
        
        $where = 
            " WHERE post_type = 'publication' 
            AND post_status = 'publish'
            AND post_excerpt LIKE '%$filter_keyword%' ";
            
        $where .= 
            " OR post_type = 'publication' 
            AND post_status = 'publish'
            AND post_title LIKE '%$filter_keyword%'";
            
        $order_by = " ORDER BY post_date DESC";

        $sql = $select . $where . $order_by;

        if ( !defined('WP_DEBUG') ):
            $wpdb->show_errors();
        endif;

        $results["query"] = array(
            "sql" => $sql,
            "year" => $filter_year,
            "month" => $filter_month,
            "keyword" => $filter_keyword
        );
        
        $results["results"] = $wpdb->get_results($sql);
        $results["found_posts"] = $wpdb->num_rows;

        return $results;

    else:
        throw new Exception("Error contacting wpdb", 1);
        exit;
    endif;
}

template.php

<?php

$results = do_search();
$query = $results["query"];
$posts = $results["results"];
$found_posts = $results["found_posts"];

//$sql = $query["sql"];
$filter_year = $query["year"];
$filter_month = $query["month"];
$filter_keyword = $query["keyword"];

// set taxonomy term type
$filter_type = isset($_GET['type']) ? $_GET['type'] : '';

// Set your response when there are no results found
function return_no_results(){
	echo '<p class="push--top">Sorry no results for this search.</p>';
}

if( $found_posts > 0 ): ?>

	<?php foreach ($posts as $post_object) : $post = get_post($post_object->ID); setup_postdata($post);?>

		<?php 
			$published_month = get_the_time(get_the_date('m')); 
			$published_year = get_the_time(get_the_date('Y')); 
			
			if (($filter_year == '' OR $filter_year == $published_year) AND ($filter_month == '' OR $filter_month == $published_month) AND (has_term($filter_type, 'publication_type', $post->ID))) :
				$match = 1;
		?>
		
				<!-- content goes here -->
				
		<?php endif; ?>

	<?php endforeach; wp_reset_postdata(); ?>

	<?php if (!$match): ?>
	
		<?php return_no_results(); ?>
		
	<?php endif ?>

<?php else: ?>

	<?php return_no_results(); ?>

<?php endif; ?>