Optional database updates to drop orphaned orders table columns and unused usermeta rows.

optional-pmpro-3-0-database-updates.php

<?php
/**
 * Optional database updates to drop orphaned orders table columns and unused usermeta rows.
 */
function run_optional_pmpro_upgrade_3_0() {
	global $wpdb;

	// PMPro Stripe Billing Limits Add On has been merged into core and no longer needs `pmpro_stripe_billing_limit` user meta.
	$sqlQuery = "
		DELETE FROM {$wpdb->usermeta}
		WHERE meta_key = 'pmpro_stripe_billing_limit'
		";
	$wpdb->query( $sqlQuery );

	// Dropping deleted order columns.
	$columns_to_drop = array(
		'couponamount',
		'certificate_id',
		'certificateamount',
	);
	foreach ( $columns_to_drop as $column ) {
		$sqlQuery = "
			ALTER TABLE {$wpdb->pmpro_membership_orders}
			DROP COLUMN {$column}
			";
		$wpdb->query( $sqlQuery );
	}
}
add_action( 'admin_init', 'run_optional_pmpro_upgrade_3_0' );