How do I identify orders with the Google Checkout Notification API (using PHP)?

Question

I am using the Google Checkout API to code a simple store. I have gotten as far as letting the user select items, edit the cart, and checkout/pay with Google Checkout. The notification API (with XML) is being used to read notifications sent by Google after receiving orders. How can I connect the order notifications with the orders information in my SQL database? Can I send an "order ID" or something like that to Google with the initial order? I have coded that portion (ordering) with the HTML API.

Thanks in advance!

Answer 1

When an order is placed, a notification is made giving you a serial number for the order. You need to store this serial number in your database against whatever internal order number you have, so that you can use the serial number to refer to the order with Google Checkout via the Notification API.

Answer 2

No. Notification and Polling are two separate concepts.

Notification is when Google Checkout sends you info as it occurs, and Polling is when you send a request for sale details at some time in the future.

Documentation for Polling is lacking on-line. That is why you - and I - have not found the answer.

Google sends an e-mail when a sale is made (or when something goes wrong with a payment), and it stores some detail in your dashboard. You can use the date or the number to Poll for the rest of the details. Exactly how to do that is lacking in the on-line documentation.

Answer 3

Use the merchant-private-data field to pass any custom data about your order.

When you get back the notification, read the custom info from the merchant-private-data field.

See this answer for a solution to a similar issue.