Example script that sets post_content = 'renewal' for renewal orders

flag-renewal-orders.php

<?php
/**
 * Flag historical renewal orders.
 *
 * wp eval-file flag-renewal-orders.php
 */

global $wpdb;

$last_processed = (int) get_transient( 'uy_last_processed_for_flagging' );
$limit_query    = 10000;

while ( true ) {
	WP_CLI::log( "Processing $limit_query orders above $last_processed." );

	$sql = "SELECT post_id FROM $wpdb->postmeta
		WHERE post_id > $last_processed
		AND meta_key = '_subscription_renewal'
		ORDER BY post_id ASC
		LIMIT $limit_query";

	$renewal_orders = $wpdb->get_results( $sql, ARRAY_A );

	if ( ! $renewal_orders ) {
		WP_CLI::log("Finished!");
		break;
	}

	$renewal_order_ids = array_map(
		static function ( $el ) {
			return $el['post_id'];
		},
		$renewal_orders
	);

	WP_CLI::log( print_r( $renewal_order_ids, true ) );

	$sql = "UPDATE $wpdb->posts
		SET post_content = 'renewal'
		WHERE ID IN (" . implode(',', $renewal_order_ids) . ")";

	$wpdb->get_results( $sql );

	$last_processed = end( $renewal_order_ids );
	set_transient( 'uy_last_processed_for_flagging', $last_processed, DAY_IN_SECONDS );
	WP_CLI::log("Set uy_last_processed_for_flagging to $last_processed. Sleeping for 3 seconds.");
	WP_CLI::log("---");
	sleep(3);
}