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POIQueryable returns null on invoking Count c#
 

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    <p>I have a problem trying to get the count out of the following query:</p> <pre><code>var usersView = PopulateUsersView(); //usersView is an IQueryable object var foo = usersView.Where(fields =&gt; fields.ConferenceRole.ToLower().Contains("role")); </code></pre> <p>Where UsersView is a class which is populated from an EF entity called users (refer to the first line in the code above)</p> <p>This is the class definition for the UsersView class:</p> <pre><code>public class UsersView { public int UserId { get; set; } public string Title { get; set; } public string Name { get; set; } public string Surname { get; set; } public string Street1 { get; set; } public string Street2 { get; set; } public string City { get; set; } public string PostCode { get; set; } public string CountryName { get; set; } public string WorkPlaceName { get; set; } public string Gender { get; set; } public string EMail { get; set; } public string Company { get; set; } public string RoleName { get; set; } public string ConferenceRole { get; set; } } </code></pre> <p>As I said trying to execute the line foo.Count() returns Null Exception and this might be because the ConferenceRole column allows Null in the database. </p> <p>Now what I can't understand is that when I invoke the same query directly on the ObjectQuery the Count of records (i.e. invoking foo2.Count()) is returned without any exceptions. </p> <pre><code>var foo2 = entities.users.Where(fields =&gt; fields.ConferenceRole.ToLower().Contains("role")); </code></pre> <p>Is it possible to the same query above but using the IQueryable usersView object instead?</p> <p>(It is crucial for me to use the usersView object rather than directly querying the entities.users entity)</p> <p>EDIT</p> <p>Below is the code from the PopulateUsersView method</p> <pre><code>private IQueryable&lt;UsersView&gt; PopulateUsersView() { using (EBCPRegEntities entities = new EBCPRegEntities()) { var users = entities.users.ToList(); List&lt;UsersView&gt; userViews = new List&lt;UsersView&gt;(); foreach (user u in users) { userViews.Add(new UsersView() { UserId = u.UserId, Title = u.Title, Name = u.Name, Surname = u.Surname, Street1 = u.Street1, Street2 = u.Street2, City = u.City, PostCode = u.Post_Code, CountryName = u.country.Name, WorkPlaceName = u.workplace.Name, Gender = u.Gender, EMail = u.E_Mail, Company = u.Company, RoleName = u.roles.FirstOrDefault().Name, ConferenceRole = u.ConferenceRole }); } return userViews.AsQueryable(); } } </code></pre> <p>Thanks</p> <p>UPDATE...</p> <p>Thanks guys I finally found a good answer to the difference between the IQueryable and the ObjectQuery objects. </p> <p>As a solution I am checking if the ConferenceRole is null and then checking with the contains method as many of you guys have said.</p>
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    1. USRyan
    1. USRyan
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    1. COI suggest you do a comparison of the two approaches: What is the content of `ConferenceRole` for entities where it is NULL in the database?
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      1. USDaniel Hilgarth
    2. COIt's string and by default it's created as null in the database.
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      1. USRyan
    3. COThat was not what I was asking. Obviously, ConferenceRole is null when you access it via the usersView, but not when you access it directly from the database. So what is it then?
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      1. USDaniel Hilgarth
 

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