CODEWITHSUNDEEP
c#linq
GPGVM
GPGVM

Reputation: 5619

Linq projection nested LIST<T> property

This query has taken a couple days but I am almost there. I have hacked my way through LINQ to entities to come up with the following from reading a lot of tutorials. However this last part I am missing.

I have two basic objects:

public class DashboardNavigation()
{
   public int Id {get; set;}
   public string Name {get; set;}
   .....etc.....
   public List<SubNav> SubDashNav {get; set;}
}

public class SubNav()
{
   ....properties....
}




var query = _mlsDashboardNavRepository.Table
        .OrderBy(x => x.Id)
        .Select(x => new
        {
            Id = x.Id,
            Name = x.Name,
            Description = x.Description,
            ImageUrl = x.ImageUrl,
            SubDashNav = _mlsSubDashNav.Table
                .Where(s => s.DashId == x.Id)
                .Select(y => new { Id = y.Id, DashId = y.DashId, Name = y.Name, Description = y.Description, ImageUrl = y.ImageUrl, IsAdvanced = y.IsAdvanced }).ToList()

        }).ToList().Select(q => new MLS_DashboardNavigation()
                            {
                                Id = q.Id,
                                Name = q.Name,
                                Description = q.Description,
                                ImageUrl = q.ImageUrl,
                                SubDashNav = ...???

                            }).ToList();

My Linq projects DashboardNavigation correctly but I can't figure out how to get SubDashNav populated???

Upvotes: 0

Views: 675

Answers (1)

Dhunt
Dhunt

Reputation: 1594

You don't need to select twice. I think this does the same thing.

var query = _mlsDashboardNavRepository.Table
    .OrderBy(x => x.Id)
    .Select(x => new MLS_DashboardNavigation()
    {
        Id = x.Id,
        Name = x.Name,
        Description = x.Description,
        ImageUrl = x.ImageUrl,
        SubDashNav = _mlsSubDashNav.Table
            .Where(s => s.DashId == x.Id).ToList()
    }).ToList();

And if you are using Entity Framework and navigation properties with DashIs as a foreign key to subNavDash table then you might even be able to do this

var query = _mlsDashboardNavRepository.Table
    .OrderBy(x => x.Id)
    .Select(x => new MLS_DashboardNavigation()
    {
        Id = x.Id,
        Name = x.Name,
        Description = x.Description,
        ImageUrl = x.ImageUrl,
        SubDashNav = x.SubDashNav
    }).ToList();

And if MLS_DashboardNavigation is the same type as _mlsDashboardNavRepository.Table you won't even need to select as that is whats returned anyway.

var query = _mlsDashboardNavRepository.Table
    .OrderBy(x => x.Id).ToList()

Upvotes: 1

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