Way to Link Order with Customer Account?

I had a customer that created an account and then for some reason when they came back to purchase their products they did not login. Is there a way to associate the order with the existing account?

You have to manually update [Order] table ([CustomerId] column) in your database

Is that something that could be added into the admin interface? I've also seen an option on another e-commerce site that will look at the email address that someone uses to register their account with and then cycles through any orders that were done previously with that same email address and automatically associates them to that customers new account.

Personally I do not think that it's really required. It'll just make things more complex. BTW, I've never seen such functionality in other shopping cart software. Anyway you can vote for this work item here

Here is an example: https://americasprinter.com/account/login?from_controller=shop&from_action=cart