I would like to use the API to POST hundreds of Sales Order Items to 1 invoice.
It seems there is no built-in way to convert 100s of Sales Orders to 1 invoice, so I thought that I could just use API to post all of the items from all of the sales orders to 1 invoice. This seems easy enough, but I need a custom field on the items to record the sales order ID #.
so, my invoice would have hundreds of lines like:
SO ID | Item | Quantity | Rate | Total
G1234 | shirt | 5 | 10 | 50
I can see how to set up a custom field on the Items.
1) I would like to know if I can POST any data to the custom field for the item when creating an Invoice.
2) If I can post dynamically to the SO ID custom field, how do I refer to it in the JSON?