Source

File: wp-includes/option.php

function delete_network_option( $network_id, $option ) {
	global $wpdb;

	if ( $network_id && ! is_numeric( $network_id ) ) {
		return false;
	}

	$network_id = (int) $network_id;

	// Fallback to the current network if a network ID is not specified.
	if ( ! $network_id ) {
		$network_id = get_current_network_id();
	}

	/**
	 * Fires immediately before a specific network option is deleted.
	 *
	 * The dynamic portion of the hook name, `$option`, refers to the option name.
	 *
	 * @since 3.0.0
	 * @since 4.4.0 The `$option` parameter was added.
	 * @since 4.7.0 The `$network_id` parameter was added.
	 *
	 * @param string $option     Option name.
	 * @param int    $network_id ID of the network.
	 */
	do_action( "pre_delete_site_option_{$option}", $option, $network_id );

	if ( ! is_multisite() ) {
		$result = delete_option( $option );
	} else {
		$row = $wpdb->get_row( $wpdb->prepare( "SELECT meta_id FROM {$wpdb->sitemeta} WHERE meta_key = %s AND site_id = %d", $option, $network_id ) );
		if ( is_null( $row ) || ! $row->meta_id ) {
			return false;
		}
		$cache_key = "$network_id:$option";
		wp_cache_delete( $cache_key, 'site-options' );

		$result = $wpdb->delete(
			$wpdb->sitemeta,
			array(
				'meta_key' => $option,
				'site_id'  => $network_id,
			)
		);
	}

	if ( $result ) {

		/**
		 * Fires after a specific network option has been deleted.
		 *
		 * The dynamic portion of the hook name, `$option`, refers to the option name.
		 *
		 * @since 2.9.0 As "delete_site_option_{$key}"
		 * @since 3.0.0
		 * @since 4.7.0 The `$network_id` parameter was added.
		 *
		 * @param string $option     Name of the network option.
		 * @param int    $network_id ID of the network.
		 */
		do_action( "delete_site_option_{$option}", $option, $network_id );

		/**
		 * Fires after a network option has been deleted.
		 *
		 * @since 3.0.0
		 * @since 4.7.0 The `$network_id` parameter was added.
		 *
		 * @param string $option     Name of the network option.
		 * @param int    $network_id ID of the network.
		 */
		do_action( 'delete_site_option', $option, $network_id );

		return true;
	}

	return false;
}