I'm using Drupal 7.x with the Entity Reference and Entity Connect modules. I have a Product Page content type that has 1 entity reference field that I'm trying to use to create user associations (i.e. - "Product A" might be associated with 2 users whereas "Product B" might be associated with 5, "Product C" only 1, etc., etc.)

I didn't use a user reference field for this because the entity connect module wouldn't work with the standard user reference field type and since everything in Drupal is moving toward using entities anyway, I figured I might as well go with it. (I use entity connect for those moments when a user doesn't exist; it allows content editors who create Product Pages to create users on the fly if the reference doesn't exist).

So from what I understood, users can be "entity referenced" because user profiles are entities themselves. This must be true because the field I'm using allows me to reference users by their username (i.e. - the auto-complete input of the entity reference field shows respective registered users when they're found) but what I need to do is reference users by their last name fields instead--which I'm having problems with.

Think of all this as a "mask" for the auto-complete. That said, how does one reference users by another field in the auto-complete input??? Surely there's a way to do this because I can't imagine that you're locked into referencing only by username...

With entity reference fields, you can attach a view to the field and I've read that this is how you can do all this... So I created a view that accepts a last name as a contextual field and made this view have the Entity Reference display. I then attached it to the field, but when I type a last name, well, nothing shows. So clearly, it doesn't work or else I did something wrong somewhere...

(This is a hairy issue, I know, but I tried to keep it short. I posted a more verbose explanation of all this on a Drupal project page, too, which has more detail if necessary: http://drupal.org/node/1906344)

Any insight into this is appreciated.