how to manage keys in LINQ with code first data model

Question

I have Created 2 database in 1 project in LINQ c#. but another database multiple tables that all table depend on each table using foreign key n unique key I want only two tables in another database but now because of key 20 table code required in my project so this solution is not suitable.

if any other solution then tells me or how to manage foreign key n unique key in LINQ using code first data model.