Question

I am trying to find a User entity in my “Domain Entity” DB Set.
The User entity is derived from a base type called Domain Entity.

I want to use the following to find a user according to his ID

User userToDelte = db.DomainEntities.OfType<User>().Find(UserID);

But I get a compiler error :

‘System.Linq.IQueryable’ does not
contain a definition for ‘Find’ and no extension method ‘Find’
accepting a first argument of type…

Why can’t I use Find() after I have used OfType<User>() ?

P.S
It is important for me to get a strongly typed User entity because it has a navigation propertiy that include all of it’s details in a separate table called “UserDetails” along with the user name and password.

Answer 1

That is because Find method is declared in DbSet not System.Linq.IQueryable. Instead of that use the Set method of DbContext to create the DbSet.

User userToDelte = db.Set<User>().Find(UserID);