Question

I’m try to do this : I’m using EF code first to map an old existing database. There’s many fields with the wrong type (ex: char(1) used as boolean) so I’ve created a wrapper class for my db context that maps perfectly to the database table. Now, I want to expose an IQueryable of my Entity type on my repository. See my example :

public class MyContext:DbContext
{
    public DbSet<WrappedEntity> WrapperEntities;
}

public class Repository
{
    private MyContext _context;

    //contructors omitted

    public IQueryable<Entity> GetEntities()
    {
        return _context.WrapperEntities; //doesn't compile, I need some convertion here
    }
}

I already have my convertion routine, the only thing missing is a way to query my DbContext thought my repository without exposing the WrappedEntity class, Is it possible and how ?

Thanks.

Answer 1

Usually you project with Queryable.Select to change the type of your query…

public IQueryable<Entity> GetEntities()
{
  return _context.WrapperEntities.Select(x => new Entity(){...});
}