How to use an SQL query for multiple meta_key and meta_value pairs with PHP from WordPress Database - example: Finding FooEvents Cancelled Tickets

sql_php_example.php

<?php
/**
 *
 * This function returns the number of canceled tickets of a specific FooEvents WooCommerce product.
 * @author Saskia Teichmann | wp-studio.dev
 *
 * @param int            $event_product_id.
 * @return int
 */
  function wpstudiodev_get_number_of_canceled_tickets($event_product_id){
    global $wpdb;
    $prefix = $wpdb->prefix;
    $all_canceled_tickets_sql = "
            SELECT *
                      FROM {$prefix}posts p
                      INNER JOIN {$prefix}postmeta pm1 
                        ON ( p.ID = pm1.post_id )
                      INNER JOIN {$prefix}postmeta pm2
                        ON ( p.ID = pm2.post_id )
                      WHERE 
                      p.post_type = 'event_magic_tickets'
                      AND p.post_status = 'publish'
                      AND ( pm1.meta_key = 'WooCommerceEventsProductID' AND pm1.meta_value = $event_product_id )
                      AND ( pm2.meta_key = 'WooCommerceEventsStatus' AND pm2.meta_value = 'Canceled' )                
          ";
    $all_canceled_tickets = $wpdb->get_results($all_canceled_tickets_sql);
    $canceled_tickets_total = count( $all_canceled_tickets );
    return $canceled_tickets_total;
  }