Lambda with different contexts

You can use Linq To Objects , that is, manipulating data in memory, also recommended < to% C #% to not cache queries. p>

Example

IList<Pessoa> Pessoas = null;
using (Dba1 dba1 = new Dba1())
{
    Pessoas = dba1.Pessoa.AsNoTracking().ToList();
}


IList<Telefone> Telefones = null;
using (Dba2 dba2 = new Dba2())
{
    Telefones = dba2.Telefone.AsNoTracking().ToList();
}


Pessoas.Join(Telefones, x => x.Id, g => g.PessoaId, (x, g) => new { x, g })
       .Select(s => new
       {
           s.g.Ddd, 
           s.g.Numero, 
           s.g.PessoaId,
           s.x.Nome
       }).ToList();

Note: Not very performative, but in specific cases can be well used, can not become rule of your application .

References:

• Linq To Objects

• DbExtensions.AsNoTracking Method (IQueryable)