Question

I need to filter a dealer based on id and the uncomplete checkins

Initially, it returned the dealer based only on id:

    // TODO: limit checkins to those that are not complete
    return this.ObjectContext.Dealers
        .Include("Groups")
        .Include("Groups.Items")
        .Include("Groups.Items.Observations")
        .Include("Groups.Items.Recommendations")
        .Include("Checkins")
        .Include("Checkins.Inspections")
        .Include("Checkins.Inspections.InspectionItems")
        .Where(d => d.DealerId == id)
        .FirstOrDefault();

As you can see the requirement is to limit the checkins.
Here’s what I did:

var query = from d in this.ObjectContext.Dealers
                            .Include("Groups")
                            .Include("Groups.Items")
                            .Include("Groups.Items.Observations")
                            .Include("Groups.Items.Recommendations")
                            .Include("Checkins.Inspections")
                            .Include("Checkins.Inspections.InspectionItems")
                            .Where(d => d.DealerId == id)
                        select new
                        {
                            Dealer = d,
                            Groups = from g in d.Groups
                                     select new
                                     {
                                         Items = from i in g.Items
                                                 select new
                                                 {
                                                     Group = i.Group,
                                                     Observations = i.Observations,
                                                     Recommendations = i.Recommendations
                                                 }
                                     },
                            Checkins = from c in d.Checkins
                                       where c.Complete == true
                                       select new
                                       {
                                           Inspections = from i in c.Inspections
                                                         select new
                                                         {
                                                             InspectionItems = i.InspectionItems
                                                         }
                                       }

                        };

            var dealer = query.ToArray().Select(o => o.Dealer).First();

            return dealer;

It works.
However, I am not convinced I am doing the right thing.

What is the best way to accomplish what I did? A stored procedure maybe?

I am not sure I even have to use Include clause anymore

Thank you.

Answer 1

Maybe you can make use of the relation fixup mechanism in the EF ObjectContexts. When you do multiple queries in the same context for entities, that are related by associations, these are resolved.
Assuming your association between Dealers and Checkins is 1:n with navigation properties on each side, you could do like:

var dealer = yourContext.Dealers
             .Where(p => p.DealerId == id)
             .FirstOrDefault();
if(dealer != null)
{
    yourContext.Checkins
           .Where(c => c.Complete && c.DealerId == dealer.DealerId)
           .ToList();

I have not tested this by now, but since EF recognises that the Checkins, it inserts into the context by the second query belong to the dealer from the first query, corresponding references are created.