Merge pull request JasperFx#149 from nieve/where-modulo

added support for modulo where queries
barryhagan · Feb 12, 2016 · 6d2f924 · 6d2f924
2 parents 9f9fb6e + 7dfe709
commit 6d2f924
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diff --git a/src/Marten.Testing/Linq/query_with_modulo_Tests.cs b/src/Marten.Testing/Linq/query_with_modulo_Tests.cs
@@ -0,0 +1,27 @@
+using System.Linq;
+using Marten.Services;
+using Marten.Testing.Fixtures;
+using Xunit;
+
+namespace Marten.Testing.Linq
+{
+    public class query_with_modulo_Tests : DocumentSessionFixture<NulloIdentityMap>
+    {
+        [Fact]
+        public void use_modulo()
+        {
+            theSession.Store(new Target{Color = Colors.Blue, Number = 1});
+            theSession.Store(new Target{Color = Colors.Blue, Number = 2});
+            theSession.Store(new Target{Color = Colors.Blue, Number = 3});
+            theSession.Store(new Target{Color = Colors.Blue, Number = 4});
+            theSession.Store(new Target{Color = Colors.Blue, Number = 5});
+            theSession.Store(new Target{Color = Colors.Green, Number = 6});
+
+            theSession.SaveChanges();
+
+            theSession.Query<Target>().Where(x => x.Number % 2 == 0 && x.Color == Colors.Blue).ToArray()
+                .Select(x => x.Number)
+                .ShouldHaveTheSameElementsAs(2, 4);
+        }
+    }
+}
diff --git a/src/Marten.Testing/Marten.Testing.csproj b/src/Marten.Testing/Marten.Testing.csproj
@@ -124,6 +124,7 @@
     <Compile Include="Linq\query_against_primitive_array_Tests.cs" />
     <Compile Include="Linq\query_running_through_the_IdentityMap_Tests.cs" />
     <Compile Include="Linq\query_with_any_within_child_collection_Tests.cs" />
+    <Compile Include="Linq\query_with_modulo_Tests.cs" />
     <Compile Include="Linq\query_with_enums_Tests.cs" />
     <Compile Include="Linq\query_with_nullable_types_Tests.cs" />
     <Compile Include="Linq\using_containment_operator_in_linq_Tests.cs" />

diff --git a/src/Marten/Linq/MartenExpressionParser.cs b/src/Marten/Linq/MartenExpressionParser.cs
@@ -203,11 +203,23 @@ private IWhereFragment buildSimpleWhereClause(IDocumentMapping mapping, BinaryEx
 
                 return new WhereFragment(sql);
             }
+            if (binary.Left.NodeType == ExpressionType.Modulo)
+            {
+                var moduloByValue = GetModuloByValue(binary);
+                return new WhereFragment("{0} % {1} {2} ?".ToFormat(jsonLocator, moduloByValue, op), value);
+            }
 
 
             return new WhereFragment("{0} {1} ?".ToFormat(jsonLocator, op), value);
         }
 
+        private static object GetModuloByValue(BinaryExpression binary)
+        {
+            var moduloExpression = binary.Left as BinaryExpression;
+            var moduloValueExpression = moduloExpression?.Right as ConstantExpression;
+            return moduloValueExpression != null ? Value(moduloValueExpression) : 1;
+        }
+
         public static object Value(Expression expression)
         {
             if (expression is PartialEvaluationExceptionExpression)