Magento2 - Copy quote fields to order fields

Question

In Magento2, i want to copy the quote custo fields into order custom fields, i.e.

say, i have created a manufacturer column in quote_item which needs to be copied into sales_order_item table, manufacturer column, during order placed.

In Magento1, it was possible through

Answer 1

To copy quote item fields to sale order item fields, we need to declare these fields in fieldset.xml

app/code/Vendor/Module/etc/fieldset.xml

<?xml version="1.0"?>

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="urn:magento:framework:DataObject/etc/fieldset.xsd">
    <scope id="global">
        <!-- Copy quote to sale order fields -->
        <fieldset id="sales_convert_quote">
            <field name="custom_attribute">
                <aspect name="to_order" />
            </field>
        </fieldset>
        <!-- Copy quote item to sale order item fields-->
        <fieldset id="quote_convert_item">
            <field name="manufacturer">
                <aspect name="to_order_item" />
            </field>
        </fieldset>
    </scope>
</config>

[EDIT]

Seem that we need to use Observer sales_model_service_quote_submit_before to assign the new fields:

Answer 2

On 2.1.3 at least, doing it through fieldset.xml does not work.

I had to use the event sales_model_service_quote_submit_before , which is fired in function submitQuote of Magento\Quote\Model\QuoteManagement

$order->setCustomerLastname($quote->getCustomerLastname());

$this->eventManager->dispatch(
                'sales_model_service_quote_submit_before',
                [
                    'order' => $order,
                    'quote' => $quote
                ]
            );