Can a Discriminator Column be part of the Primary Key in Doctrine2?

[woulsessy]

I'm using Single Table Inheritance in Doctrine2 to store OAuth credentials for multiple services. I'd like to use the service's id as the primary key; however, that's not unique across all services. I've setup the database to use the discriminator column and the service's id as the primary key, but I can't find a way to make Doctrine use the discriminator column as the key (in addition to the discriminator column). I'm using docblock annotations, and if I add the discriminator column as an @Id field I get an error:\[code\]Duplicate definition of column...in a field or discriminator column mapping.\[/code\]If I only define the field as the discriminator column, any overlapping service ids update all the matching rows.Anyway to make this work, other than just using an autogenerated it value?