In an app with EF6.0, I have two DbContext's created by model first,
Now I need to do a join on two entities,
How can I do this?
If you can use stored procedures, this is a case for it. The proc can join the two entities at the database level across databases. Whichever db is appropriate, you can then map that proc in your entities model and use it. I say 'if you can' because I've seen shops that prohibit all SP's in favor of only EF.