Fixes expression tree changes

src/Umbraco.Core/Persistence/Querying/ModelToSqlExpressionVisitor.cs

@@ -61,7 +61,10 @@ namespace Umbraco.Core.Persistence.Querying
                 return string.Empty;
             }
 
-            if (m.Expression != null && m.Expression.Type != typeof(T) && TypeHelper.IsTypeAssignableFrom<IUmbracoEntity>(m.Expression.Type))
+            if (m.Expression != null 
+                && m.Expression.Type != typeof(T) 
+                && TypeHelper.IsTypeAssignableFrom<IUmbracoEntity>(m.Expression.Type)
+                && EndsWithConstant(m) == false)
             {
                 //if this is the case, it means we have a sub expression / nested property access, such as: x.ContentType.Alias == "Test";
                 //and since the sub type (x.ContentType) is not the same as x, we need to resolve a mapper for x.ContentType to get it's mapped SQL column
@@ -101,5 +104,24 @@ namespace Umbraco.Core.Persistence.Querying
             return string.Empty;
 
         }
+
+        /// <summary>
+        /// Determines if the MemberExpression ends in a Constant value
+        /// </summary>
+        /// <param name="m"></param>
+        /// <returns></returns>
+        private bool EndsWithConstant(MemberExpression m)
+        {
+            Expression expr = m;
+            
+            while (expr is MemberExpression)
+            {
+                var memberExpr = expr as MemberExpression;
+                expr = memberExpr.Expression;
+            }
+            
+            var constExpr = expr as ConstantExpression;
+            return constExpr != null;
+        }
     }
 }

src/Umbraco.Tests/Persistence/Querying/ExpressionTests.cs

@@ -17,6 +17,23 @@ namespace Umbraco.Tests.Persistence.Querying
     [TestFixture]
     public class ExpressionTests : BaseUsingSqlCeSyntax
     {
+        [Test]
+        public void Equals_Claus_With_Two_Entity_Values()
+        {
+            var dataType = new DataTypeDefinition(-1, "Test")
+            {
+                Id = 12345
+            };
+            Expression<Func<PropertyType, bool>> predicate = p => p.DataTypeDefinitionId == dataType.Id;
+            var modelToSqlExpressionHelper = new ModelToSqlExpressionVisitor<PropertyType>();
+            var result = modelToSqlExpressionHelper.Visit(predicate);
+
+            Debug.Print("Model to Sql ExpressionHelper: \n" + result);
+
+            Assert.AreEqual("([cmsPropertyType].[dataTypeId] = @0)", result);
+            Assert.AreEqual(12345, modelToSqlExpressionHelper.GetSqlParameters()[0]);
+        }
+
         [Test]
         public void Can_Query_With_Content_Type_Alias()
         {