Check if required tables exist and create them if they don't.

catchup_v3.php

<?php
/**
 * Check if  required tables exist and create them if they don't.
 * This function is used to catch up missing tables that should have been created by Paid Memberships Pro when update to v3
 * 
 * link: TBD
 *
 * You can add this recipe to your site by creating a custom plugin
 * or using the Code Snippets plugin available for free in the WordPress repository.
 * Read this companion article for step-by-step directions on either method.
 * https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
 */
function pmpro_catch_up_missing_tables() {
	global $wpdb;

	//This may be modified to include other tables as needed
	$missed_tables = array(
		"{$wpdb->prefix}pmpro_subscriptions",
		"{$wpdb->prefix}pmpro_subscriptionmeta",
		"{$wpdb->prefix}pmpro_groups",
		"{$wpdb->prefix}pmpro_membership_levels_groups"
	);

	// Get all table names from the database
	$all_tables = $wpdb->get_col( "SHOW TABLES" );

	// Check if all required tables exist
	foreach ( $missed_tables as $table_name ) {
		if ( !in_array( $table_name, $all_tables ) ) {
			// Table is missing, call the dbDelta function to create it
			pmpro_db_delta();
			break;
		}
	}
}

add_filter('admin_init', 'pmpro_catch_up_missing_tables');