实体框架 - 如何过滤渴望加载的导航/关系属性？

Question

I have the following Entity Framework 4.1 entities and relationships

Concert ConcertId, AdministratorUserId, Name, IsDeleted

Booking BookingId, ConcertId, UserId, IsDeleted

UserId , UserId, Name, IsDeleted

Relationships Concert 1.....M Booking 1....1 User

Now I am trying to select all the Concerts for a particular AdminstratorUserId but also include all the Bookings for each Concert and also the User details for each booking. I would also like to apply a filter where IsDeleted == false for each Concert, Booking and User. I Would like to return a List of Concerts which have their Booking and User details maintained as navigational properties.

In SQL, this is what I am trying to achieve:

SELECT *
FROM concert c, booking b, user u
WHERE c.ConcertId = b.ConcertId AND b.UserId = u.UserId AND c.AdministratorId = 10
AND c.IsDeleted = false AND b.IsDeleted = false AND u.IsDeleted = false

As far as I am aware, using the "Include" method to eager load, doesn't allow filtering or subqueries of the child entity it loads in; it returns all records for that join, so I tried to use an anonymous projection as follows:

int adminId = 10;

var concerts = _context.Concerts
    .Where(p => p.AdministratorId == adminId && p.IsDeleted == false)
    .Select(p => new {
        Concerts = p,
        Bookings = p.Bookings
            .Where(q => q.IsDeleted == false && q.User.IsDeleted == false)
            .Select(r => new {
                Bookings = r,
                User = r.User
            })
            .AsEnumerable()
            .Select(q => q.Bookings)
    })
    .AsEnumerable()
    .Select(p => p.Concerts)
    .ToList();

However, this is still returning all records and not filtering out the ones where IsDeleted = true. Anyone have any ideas, or suggestions how I can clean up this monstrous query?

I have also tried a method similar to this (http://blogs.msdn.com/b/alexj/archive/2009/06/02/tip-22-how-to-make-include-really-include.aspx), which again fails (returns all bookings even deleted ones):

var concertsQuery = (ObjectQuery<Concert>)_context.Concerts
    .Where(p => p.UserId == userId
        && p.IsDeleted == false
        && p.Bookings.Any(q => q.IsDeleted == false && q.User.IsDeleted == false)
    );

var concerts = concertsQuery.Include("Bookings").Include("Bookings.User").ToList();

Answer 1

Get rid of those AsEnumerable they will turn your query to linq-to-objects:

var concerts = _context.Concerts
    .Where(p => p.AdministratorId == adminId && p.IsDeleted == false)
    .Select(p => new {
        Concerts = p,
        Bookings = p.Bookings
            .Where(q => q.IsDeleted == false && q.User.IsDeleted == false)
            .Select(r => new {
                Bookings = r,
                User = r.User
            })
    })
    .ToList();

Answer 2

So, the way I've managed to resolve this issue is by running the LINQ query as per Ladislav's answer, but then using the anonymous object to re-attach the individual objects to their correct relational properties as below:

var concertResult = new List<Concert>();

foreach (var concertObject in concerts)
{
    var concert = concertObject.Concert;

    foreach (var bookingObject in concertObject.Bookings)
    {
        var booking = bookingObject.Booking;
        booking.User = bookingObject.User;
        concert.Bookings.Add(booking);
    }
    concertResult.Add(concert);
}