How do I insert categories in products in wordpress by code?

December 24, 2022

I would like to insert (not replace) categories that already exists in my website wordpress.
I tried this way:

global $wpdb;
$products = $wpdb->get_results("SELECT ID FROM `" . $wpdb->prefix . "posts` where post_type='product'");

foreach ($products as $product) {
    $array = [];
    array_push($array, 1021);
    array_push($array, 1042);
    array_push($array, 1040);
    wp_set_post_categories(38691, $array, true);
}

But unfortunately my code is not working. The numbers 1021, 1042, 1040 is the category ID and 38691 is the product ID. Someone can help me?

>Solution :

You could use wp_set_post_terms() to insert categories.

global $wpdb;
$products = $wpdb->get_results("SELECT ID FROM `" . $wpdb->prefix . "posts` where post_type='product'");

foreach ($products as $product) {
    $product_id = $product->ID;
    $categories = array(1021, 1042, 1040);

    wp_set_post_terms($product_id, $categories, 'product_cat', true);
}

The true tells WordPress to append new categories instead of replacing them