CRUD objects vs updating meta
update_post_meta()
set_stock_status(), set_stock_quantity()
WooCommerce REST API

Updating Product Stock Programmatically

May 23, 2023

Since I’ve been working a lot lately with synchronising product stock quantities between multiple WooCommerce stores or within a WordPress Multisite network, I can share with you some interesting insights how it is working.

CRUD-objects vs Updating Product Meta Directly

Trying to update product stock using update_post_meta() function

Let’s begin with the thing that product stock information is stored in the post meta wp_postmeta table for now. WooCommerce has plans to move on to a custom database table, but it is just their plans in the future.

The meta keys used:

_manage_stock – whether stock managemant is turned on or not.
_stock – product stock quantity (stock management is on).
_stock_status – instock, outofstock etc (stock management is off).

So, when you find those values in the database, the first thing that may come to your mind is to do something like this:

$product_id = 123;

update_post_meta( $product_id, '_manage_stock', 'yes' ); // yes or no
update_post_meta( $product_id, '_stock', 100 );
update_post_meta( $product_id, '_stock_status', 'instock' );

And it is actually working without even refreshing the caches:

But this method doesn’t work properly with product variations. Using WC_Product_Variable::sync() or wc_delete_product_transients() doesn’t help.

set_stock_status() and set_stock_quantity() methods of WC_Product

But the most correct way to update product stock data is to use CRUD layers of course.

$product_id = 123;
$product = wc_get_product( $product_id ); // object of WC_Product class
// for variations
// $product = wc_get_product_object( 'variation', $product_id );

$product->set_manage_stock( true ); // true/false
$product->set_stock_quantity( 100 );
// $product->set_stock_status( 'instock' );

// always
$product->save();

In this case you don’t even need to use set_stock_status() method because WooCommerce will figure it out itself that this specific product is in stock now.

Using WooCommerce REST API

$product_id = 123;

wp_remote_request(
	"https://YOUR STORE/wp-json/wc/v3/products/{$product_id}",
	array(
		'method' => 'PUT',
		'headers' => array(
			'Authorization' => 'Basic ' . base64_encode( "$login:$pwd" )
		),
		'body' => array(
			'manage_stock' => true,
			//'stock_status' => 'instock',
			'stock_quantity' => 100,
		)
	)
);

If you don’t know where to get $login and $pwd values, please read this.

In order to make it work for product variations just change the endpoint to /wp-json/wc/v3/products/{$product_id}/variations/{$variation_id}.

# WooCommerce, Product inventory, REST API