Hi,
i'm new with DB design.
I have to design an Entity-Relationship Diagram for my application in order to handle tha changes made to an entity.

The original application deal with DOCUMENT and CONTACT entities and the SEND_TO relationship.



------------ (M) (N) ----------
|DOCUMENT |-------< SEND_TO > -------|CONTACT|
------------ ----------

Now STATE and USER entities need to be added to the project.
A document can have one or more STATE during its lifecycle.
I need to keep track of which user change the document's state.

How can i model this in the ERD ?
thanks.

Do you think a ternary relationship DOCUMENT-USER-STATE could be the solution ?

I'd create copies of each table to maintain historical records and keep them updated with triggers.