Docs need a note on foreign key references to user

[MichaelXavier]

This is from a discussion between myself, @denibertovic, and @bitemyapp. Because of the way QQ scopes things, schema.txt in this repo is not in the same scope when the user includes the decls into their own app. The result is that persistent can't figure out that SnapAuthUserId is a primary key and thus if you reference it in another table, it will not create a foreign key. The solution is to manually tell persistent's TH that the column is a reference.

[MichaelXavier]

Working example: http://dpaste.com/35XTE73

[denibertovic]

The dpaste I shared with you has been set to expire (and apparently has) so I'm sharing
the code here:

import qualified Snap.Snaplet.Auth.Backends.Persistent as SP

share [mkPersist sqlSettings, mkMigrate "migrateAll"] $ [persistLowerCase|
  SomeStuffz
    userId SP.SnapAuthUserId Eq reference=snap_auth_user
    createdAt UTCTime default=CURRENT_TIMESTAMP
  deriving Eq Show Generic
|] ++ SP.authEntityDefs

[bitemyapp]

@denibertovic you can make it highlight that as Haskell code in the following manner:

import Blah (myCode)

Example:

import Blah (myCode)

[denibertovic]

@bitemyapp Yeah I know. Just didn't think about it at the moment. Thanks, I've updated the snippet.

[bitemyapp]

@denibertovic cheers.

Also is it me or is Github missing a "view source" button for comments?

[denibertovic]

I don't remember seeing that so it might be just you. :P

[bitemyapp]

@denibertovic I mean it should be added. It's a turn of phrase.

[denibertovic]

Ah. Indeed. :)