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POLINQ query using TPH inheritance - get derived class ICollection count
 

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  1. POLINQ query using TPH inheritance - get derived class ICollection count
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    <p>I am trying to figure out how to get the count of ProjectSummaryVotes on a specific ProjectDoc.OfType. The query works but the ProjectSummaryVote attribute is null, which means I get a null value error. Is this doable? Should I abandon TPH inheritance if I need to do this? </p> <p>Model:</p> <pre><code>public class Project { public int ProjectID { get; set; } public virtual ICollection&lt;ProjectDoc&gt; ProjectDoc { get; set; } } public abstract class ProjectDoc { public int ProjectDocID { get; set; } public int ProjectID { get; set; } public string DocTitle { get; set; } public string Status { get; set; } public DateTime DateCreated { get; set; } public virtual Project Project { get; set; } public virtual ICollection&lt;Comment&gt; Comment { get; set; } } public class Summary : ProjectDoc { [DataType(DataType.MultilineText)] public string Text { get; set; } public ICollection&lt;ProjectSummaryVote&gt; ProjectSummaryVote { get; set; } } public class ProjectSummaryVote { public int ProjectSummaryVoteID { get; set; } public int ProjectDocID { get; set; } public bool Vote { get; set; } public virtual Summary Summary { get; set; } public virtual User User { get; set; } } </code></pre> <p>Query:</p> <pre><code> Project project = db.Projects .Include(i =&gt; i.User) .Include(i =&gt; i.ProjectDoc) .SingleOrDefault(x =&gt; x.ProjectID == id); </code></pre> <p>Attempt to get the count that throws an error.</p> <pre><code> var trueCount = Model.ProjectDoc.OfType&lt;Literrater.Models.Summary&gt;() .Where(s =&gt; s.Status == "Active") .SelectMany(v =&gt; v.ProjectSummaryVote.Where(s =&gt; s.Vote == true)) .Count(); </code></pre>
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    1. USabatishchev
    1. USJed Grant
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    1. COWould you care to share the error?
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      1. POLINQ query using TPH inheritance - get derived class ICollection count
      1. USJacco
    2. COThe error is just "Value cannot be null." It's not connecting the ProjectSummaryVote record. There are three votes for the Summary. Not sure how to resolve it.
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      1. POLINQ query using TPH inheritance - get derived class ICollection count
      1. USJed Grant
    3. COWhat does Literrater.Models.Summary look like?
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      1. POLINQ query using TPH inheritance - get derived class ICollection count
      1. USNasmi Sabeer
 

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