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POCreating Union fail with Entity framework
 

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  1. POCreating Union fail with Entity framework
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    <p>I want to union two list in entity framework. In one of the union part, I have a collection and in the other one, the collection is empty. I'm trying to put the collection to empty but it doesn't work...</p> <pre><code>var query = Context.Assignments.AsQueryable(); var workItemQuery = Context.WorkItems.AsQueryable(); var assigments = query.Select(o =&gt; new WorkItemAssignment() { EndDate = o.WorkItem.EndDate, StartDate = o.WorkItem.StartDate, IsExternal = o.Resource.IsExternalEmp ? Resources.External : Resources.Internal, ResourceAssignedName = o.Resource.FirstName + " " + o.Resource.LastName, RoleName = o.Role.Name, Specialties = o.AssignmentSpecialties.Select(a =&gt; a.Specialty.Name), WorkItemName = o.WorkItem.Name, WorkItemOwner = o.WorkItem.OwnerResource.FirstName + " " + o.WorkItem.OwnerResource.LastName, WorkItemStatus = o.WorkItem.WorkItemStatus.Name, Days = o.Days.Value, Percentage = o.Percentage.Value, RequestId = o.WorkRequestAllocationId != null &amp;&amp; o.WorkRequestAllocationId != Guid.Empty ? o.WorkRequestAllocation.WorkRequest.RequestId : (int?) null }); var workItemAssignments = workItemQuery.Select(o =&gt; new WorkItemAssignment() { EndDate = o.EndDate, StartDate = o.StartDate, IsExternal = "N/A", ResourceAssignedName = "N/A", RoleName = "N/A", RoleProficiency = "N/A", Specialties = Enumerable.Empty&lt;string&gt;().AsQueryable(), //DO NOT WORK !!! WorkItemName = o.Name, WorkItemOwner = o.OwnerResource.FirstName + " " + o.OwnerResource.LastName, WorkItemStatus = o.WorkItemStatus.Name, Days = null, Percentage = null, RequestId = null }); return assigments.Union(workItemAssignments); </code></pre> <p>error message:</p> <blockquote> <p>LINQ to Entities does not recognize the method 'System.Collections.Generic.IEnumerable`1[System.String] EmptyString' method, and this method cannot be translated into a store expression.</p> </blockquote> <p>When I remove the properties "Specialities" from my 2 queries, it works...</p> <p>EDIT:</p> <p>Because of the first answer, I want to clarify that I really need to stay in the entity context to keep my <code>IQueryable</code> without having my list materialize. My Kendo grid is doing some filtering / paging, and I want to send it a <code>IQueryable</code>.</p> <p>UPDATE 2:</p> <p>After using the solution of @Moho, It was only missing an <code>IEqualityComparer</code> that removed my collection from being compared between the 2 queries.</p> <pre><code>return assigments.Union(workItemAssignments ,assignmentEqualityComparer); </code></pre>
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    1. This table or related slice is empty.
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    1. USHemadeus
    1. USHemadeus
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
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      1. POCreating Union fail with Entity framework
      1. This table or related slice is empty.
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    1. COIs it an option to just not set that property and let it be null, or whatever other default value it would have?
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    2. COpost `workItemQuery`
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      1. USMoho
    3. COI've added workItemQuery. There is also some filtering after, but in this context, it's not really important.
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      1. USHemadeus
 

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