private function has_user_earned() {

		global $wpdb;

		$count = (int) $wpdb->get_var(
			$wpdb->prepare(
				"
			SELECT COUNT( pm.meta_id )
			FROM {$wpdb->postmeta} AS pm
			JOIN {$wpdb->prefix}lifterlms_user_postmeta AS upm ON pm.post_id = upm.meta_value
			WHERE pm.meta_key = '_llms_certificate_template'
			  AND pm.meta_value = %d
			  AND upm.meta_key = '_certificate_earned'
			  AND upm.user_id = %d
			  AND upm.post_id = %d
			  LIMIT 1
			;",
				array( $this->certificate_template_id, $this->userid, $this->lesson_id )
			)
		);

		/**
		 * Deprecated.
		 *
		 * @since Unknown.
		 * @deprecated 6.0.0 Filter `llms_certificate_has_user_earned` is deprecated in favor of `llms_earned_certificate_dupcheck`.
		 *
		 * @param boolean               $has_earned Whether or not the certificate has been earned.
		 * @param LLMS_Certificate_User $user_cert  The user certificate object.
		 */
		return apply_filters_deprecated( 'llms_certificate_has_user_earned', array( ( $count >= 1 ), $this ), 'llms_earned_certificate_dupcheck' );

	}