title: where does cutom field in edit page woocommerce save value in DB
body: <p>i've created custom field with below code :</p>
  <pre><code>// Display Fields
  add_action('woocommerce_product_options_general_product_data', 'woocommerce_product_custom_fields');
  
  // Save Fields
  add_action('woocommerce_process_product_meta', 'woocommerce_product_custom_fields_save');
  
  
  function woocommerce_product_custom_fields()
  {
      global $woocommerce, $post;
      echo '&lt;div class=&quot;product_custom_field&quot;&gt;';
      //Custom Product Number Field
      woocommerce_wp_text_input(
          array(
              'id' =&gt; '_custom_product_number_field',
              'placeholder' =&gt; 'Custom Product Number Field',
              'label' =&gt; __('Custom Product Number Field', 'woocommerce'),
              'type' =&gt; 'number',
              'custom_attributes' =&gt; array(
                  'step' =&gt; 'any',
                  'min' =&gt; '0'
              )
          )
      );
  }
  function woocommerce_product_custom_fields_save($post_id)
  {
      // Custom Product Text Field
      $woocommerce_custom_product_text_field = $_POST['_custom_product_text_field'];
      if (!empty($woocommerce_custom_product_text_field))
          update_post_meta($post_id, '_custom_product_text_field', esc_attr($woocommerce_custom_product_text_field));
  // Custom Product Number Field
      $woocommerce_custom_product_number_field = $_POST['_custom_product_number_field'];
      if (!empty($woocommerce_custom_product_number_field))
          update_post_meta($post_id, '_custom_product_number_field', esc_attr($woocommerce_custom_product_number_field));
  // Custom Product Textarea Field
      $woocommerce_custom_procut_textarea = $_POST['_custom_product_textarea'];
      if (!empty($woocommerce_custom_procut_textarea))
          update_post_meta($post_id, '_custom_product_textarea', esc_html($woocommerce_custom_procut_textarea));
  
  }
  </code></pre>
  <p>but i don't know where this field save in DB?
  can i save value in desired table how ?
  if you know answear pleace will help me .</p>