John Davidson

Message:

I've started Wordpress 1 month ago and i've just done my first hook into the website (just to add/remove an estimated delivery date).

Once i've had this I was thinking that I've broke the website (LMAO) but it was just a postmeta problem. The postmeta value just need to be added on on every single products and be turned to yes.

My problem is that I don't want to do it manually (164 products will be long). Is there a way to do it with some SQL or better add the checkbox to the multi-selection menu in the All product page so everyone is editing the site can use it ?
Thanks !

NOTE : I'm a newbie with WP but not with PHP and SQL

---

My Answer:
To add a custom field to multiple products in WordPress, you can use SQL queries or create a custom function to update the postmeta values for each product. Here's a general outline of how you can achieve this:

1. Using SQL queries:
- First, identify the postmeta key for the custom field you want to add (e.g., 'estimated_delivery_date').
- Use a SQL query to update the postmeta value for all products. For example:
sql
UPDATE wp_postmeta SET meta_value = 'yes' WHERE meta_key = 'estimated_delivery_date';

- Make sure to replace 'wp_' with your actual WordPress database prefix.

2. Creating a custom function:
- You can create a custom PHP function to update the postmeta values for all products. Here's an example function that you can add to your theme's functions.php file:
php
function update_custom_field_for_all_products() {
$args = array(
'post_type' => 'product',
'posts_per_page' => -1,
);
$products = new WP_Query($args);

if ($products->have_posts()) {
while ($products->have_posts()) {
$products->the_post();
update_post_meta(get_the_ID(), 'estimated_delivery_date', 'yes');
}
}
wp_reset_postdata();
}
add_action('init', 'update_custom_field_for_all_products');

- This function will update the 'estimated_delivery_date' custom field for all products of the 'product' post type.

3. Adding a checkbox to the multi-selection menu:
- If you want to add a checkbox to the All Products page in the WordPress admin, you can create a custom meta box using the add_meta_box() function. This will allow users to easily update the custom field for multiple products at once.
- Here's an example of how you can add a custom meta box:
php
function add_custom_meta_box() {
add_meta_box('estimated_delivery_date_meta_box', 'Estimated Delivery Date', 'render_custom_meta_box', 'product', 'side', 'default');
}

function render_custom_meta_box($post) {
$value = get_post_meta($post->ID, 'estimated_delivery_date', true);
?>
Estimated Delivery Date
>
}

function save_custom_meta_box($post_id) {
if (isset($_POST['estimated_delivery_date'])) {
update_post_meta($post_id, 'estimated_delivery_date', $_POST['estimated_delivery_date']);
} else {
delete_post_meta($post_id, 'estimated_delivery_date');
}
}

add_action('add_meta_boxes', 'add_custom_meta_box');
add_action('save_post', 'save_custom_meta_box');

- This code will add a custom meta box to the product edit screen in the WordPress admin, allowing users to check or uncheck the 'Estimated Delivery Date' checkbox for each product.

Choose the method that best suits your needs and technical expertise. Make sure to backup your database before making any changes.