WordPress: How to Query by Custom Fields in WordPress?

Sometimes, we want to query the database for based on some custom fields we have set. With WordPress you can achieve this easily.

Let say, you have a date field for the event post type and you want to get all the records which are going to end today or in future.

$now = new DateTime(current_time('mysql'));
$args = array(
    'post_type' => 'event',
    'meta_query' => array(
            'key' => 'start_date_time',
            'value' => $now->format('Y-m-d H:i:s'),
            'compare' => '>=',
            'type' => 'DATETIME'
$query = new WP_Query($args);

if ($query->have_posts()) : while ($query->have_posts()) : $query->the_post(); 

...Your code here...

endwhile; endif; 

Querying in WordPress sometimes really gets complicated. Hopefully, with the above example it makes it easy for you to understand how things work. Leave a comment below for any suggestions to further improve the above concept.