diff --git a/Course/DataModels/DataModels.csproj b/Course/DataModels/DataModels.csproj
index 132c02c..c68ed43 100644
--- a/Course/DataModels/DataModels.csproj
+++ b/Course/DataModels/DataModels.csproj
@@ -6,4 +6,8 @@
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
+  <ItemGroup>
+    <Folder Include="Models\" />
+  </ItemGroup>
+
 </Project>
diff --git a/Course/DataModels/IId.cs b/Course/DataModels/IId.cs
new file mode 100644
index 0000000..5eecb4f
--- /dev/null
+++ b/Course/DataModels/IId.cs
@@ -0,0 +1,7 @@
+namespace DataModels
+{
+    public interface IId
+    {
+        int Id { get; }
+    }
+}