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PORepresent View Without Key in Entity Framework
 

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    <p>I'm using a model produced with Devart Entity Developer (.edml file, which I understand is mostly similar to .edmx) to generate Entity classes whose relations are initialized in a DbContext class. The database schema specifies no PK for View1, and all columns are nullable. But the code generation assumes that for views lacking a primary key, all columns are the key. I.e., the .ssdl has all columns under the Key element and the DbContext has .IsRequired() specified on all, like so:</p> <p>ssdl excerpt:</p> <pre><code>... &lt;EntityType Name="View1"&gt; &lt;Key&gt; &lt;PropertyRef Name="FirstCol" /&gt; &lt;PropertyRef Name="Col2" /&gt; &lt;PropertyRef Name="LastCol" /&gt; &lt;/Key&gt; &lt;Property Name="FirstCol" Type="VARCHAR2" Nullable="false" MaxLength="4000" /&gt; &lt;Property Name="Col2" Type="VARCHAR2" Nullable="false" MaxLength="120" /&gt; &lt;Property Name="LastCol" Type="VARCHAR2" Nullable="false" MaxLength="20" /&gt; &lt;/EntityType&gt; .... </code></pre> <p>From DbContext:</p> <pre><code>protected override void OnModelCreating(DbModelBuilder modelBuilder) { #region View1 modelBuilder.Entity&lt;View1&gt;() .HasKey(p =&gt; new { p.FirstCol, p.Col2, p.LastCol}) .ToTable("View1", "Owner"); // Properties: modelBuilder.Entity&lt;View1&gt;() .Property(p =&gt; p.FirstCol) .HasColumnName("FirstCol") .IsRequired() .HasMaxLength(4000) .HasColumnType("VARCHAR2"); modelBuilder.Entity&lt;View1&gt;() .Property(p =&gt; p.Col2) .HasColumnName("Col2") .IsRequired() .HasMaxLength(120) .HasColumnType("VARCHAR2"); modelBuilder.Entity&lt;View1&gt;() .Property(p =&gt; p.LastCol) .IsRequired() .HasMaxLength(20) .HasColumnType("VARCHAR2"); </code></pre> <p>This causes a NullReferenceException when querying would return a row with one of the PK columns having null value.</p> <p>Is there a way to represent a view in EF without specifying keys or altering the database schema? I've found this: <a href="http://elegantcode.com/2012/03/15/querying-entityframework-views-without-a-key/" rel="nofollow">http://elegantcode.com/2012/03/15/querying-entityframework-views-without-a-key/</a> </p> <p>Is this the preferred solution? I suppose I could use DefiningQuery as well, but this seems to duplicate the sql that was used to generate the view?</p>
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