Change Woocommerce Stock Status

woocommerce_update_stock_status.php

<?php

/**
 * set the stock status for all products in your WooCommerce store
 * $from is the searched value
 * $signal is the operator (< or > ..)
 * $to is the target to be defined
 * @return void
 */
function woocommerce_update_stock_status($from,$signal,$to){
  global $wpdb;

	// set all status for products with 0 or less stocked quantity
	$sql = "UPDATE $wpdb->postmeta stock, (SELECT DISTINCT post_id FROM $wpdb->postmeta WHERE meta_key = '_stock' AND meta_value $signal $from ) id SET stock.meta_value = '$to' WHERE stock.post_id = id.post_id AND stock.meta_key = '_stock_status';";

	// run queries
	$wpdb->query( $sql );
}