How to include child properties using Entity Framework

Question

I am having a hard time figuring this out. The examples out there are not using async calls.

How do I use Include when making a get call for a single object by id?

Do I need to get rid of the async call? I need to include the matching

ExerciseRepetitions && ExerciseImages

Also how could I add a

.Where(k => k.IsHidden != true)

for each child model?

[Route("")]
public IQueryable<Exercise> GetExercises()
{
    var result = db.Exercises
        .Include(c => c.ExerciseRepetitions)
        .Include(o => o.ExerciseImages)
        .Where(k => k.IsHidden != true);
    return result;
}

// GET: api/Exercises/5
[Route("{id:int}")]
[ResponseType(typeof(Exercise))]
public async Task<IHttpActionResult> GetExercise(int id)
{
    Exercise exercise = await db.Exercises.FindAsync(id);

       ///// I need this call to return ExerciseRepetitions &&  ExerciseImages  as nested arrays. Also I need to filter out any object that has  IsHidden = true.

    if (exercise == null)
    {
        return NotFound();
    }

    return Ok(exercise);
}

ok good to know. i can filter on client. how about just including — texas697, May 07 '16 at 22:05

CodeNotFound · Accepted Answer · 2016-05-07T22:45:38.553

2

You can't filter entities through the Include extension method.

You can do the following by explicit loading the collection properties. Explicit loading let you filter the collection that you're loading like this:

if(exercise != null)
{
    await db.Entry(exercise)
             .Collection(p => p.ExerciseRepetitions)
             .Query()
             .Where(p => !p.IsHidden)
             .LoadAsync();

    await db.Entry(exercise)
             .Collection(p => p.ExerciseImages)
             .Query()
             .Where(p => !p.IsHidden)
             .LoadAsync();
}

edited May 07 '16 at 22:45

answered May 07 '16 at 22:35

CodeNotFound

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looks good, could u show me how to plug it in? Do I need to get rid of the async method and use something else? – texas697 May 07 '16 at 22:38
1

`var exercise = db.Exercises.Find(id); if (exercise != null) { /* here comes the explicit loading */ }` – Gabor May 07 '16 at 22:41
I updated my answer to ad @Gabor note and use LoadAsync async method instead of Load. – CodeNotFound May 07 '16 at 22:46
thanks a lot for your help! – texas697 May 07 '16 at 22:53
Note that for this to work properly, lazy loading must be disabled. Otherwise accessing the collections will reload them unfiltered. – Gert Arnold May 08 '16 at 07:40

How to include child properties using Entity Framework

1 Answers1