How can I create blog specific database table in multisite?

Question

I am creating a plugin, that supposed to work on WP multisite yesterday. I've installed WP multisite on my server. While testing I found out that register_activation_hook created 1 table on the main blog only, while I have 2 more blogs.

Here is how I create the tables now:

global $wpdb;
require_once(ABSPATH . 'wp-admin/includes/upgrade.php');
$table_name = $wpdb->prefix . "pm_services";
$table = "CREATE TABLE $table_name (
  ID bigint(20) NOT NULL AUTO_INCREMENT,
  service_id bigint(20) NOT NULL,
  name varchar(200) CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL,
  UNIQUE KEY cuunique (`ID`)
  );";
dbDelta($table);

Is there a way to creating this table for every blog on the network upon activation ?

Answer 1

The basic process - on activation, check if is_multisite, get all of the sites with wp_get_sites, loop over the results with foreach and switch_to_blog for each site ID, and create the table.

You'll also need to hook the wpmu_new_blog action, check if is_plugin_active_for_network, switch to that blog ID and run your activation code, so sites added after activation have their table created. Don't forget to switch back to the original blog ID after you run your activation.