fix forgot to specify second param.

PoweredSoft.DynamicLinq.Test/ConstantTests.cs

@@ -0,0 +1,73 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using PoweredSoft.DynamicLinq.Dal.Pocos;
+using PoweredSoft.DynamicLinq.Extensions;
+
+namespace PoweredSoft.DynamicLinq.Test
+{
+    internal class ConstantTestClass
+    {
+        public int Id { get; set; }
+        public int? ForeignKey { get; set; }
+        public string Text { get; set; }
+    }
+
+    [TestClass]
+    public class ConstantTests
+    {
+        internal List<ConstantTestClass> Posts { get; set; } = new List<ConstantTestClass>()
+        {
+            new ConstantTestClass { Id = 1, ForeignKey = null, Text = "Hello" },
+            new ConstantTestClass { Id = 2, ForeignKey = 1, Text = "Hello 2" },
+            new ConstantTestClass { Id = 3, ForeignKey = 2, Text = "Hello 3" },
+            new ConstantTestClass { Id = 4, ForeignKey = null, Text = "Hello 4" },
+        };
+
+        [TestMethod]
+        public void LeaveAsIs()
+        {
+            try
+            {
+                Posts
+                    .AsQueryable()
+                    .Query(t => t.Equal("ForeignKey", 1, QueryConvertStrategy.LeaveAsIs));
+
+                Assert.Fail("Should have thrown an exception");
+            }
+            catch(Exception ex)
+            {
+                
+            }
+
+            Assert.IsTrue(Posts.AsQueryable().Query(t => t.Equal("Id", 1, QueryConvertStrategy.LeaveAsIs)).Any());
+        }
+
+        [TestMethod]
+        public void SpecifyType()
+        {
+            Assert.IsTrue(Posts.AsQueryable().Query(t => t.Equal("ForeignKey", 1, QueryConvertStrategy.SpecifyType)).Any());
+            Assert.IsTrue(Posts.AsQueryable().Query(t => t.Equal("Id", 1, QueryConvertStrategy.SpecifyType)).Any());
+
+            try
+            {
+                Posts.AsQueryable().Query(t => t.Equal("Id", "1", QueryConvertStrategy.SpecifyType));
+                Assert.Fail("Should have thrown an exception");
+            }
+            catch
+            {
+
+            }
+        }
+
+        [TestMethod]
+        public void ConvertConstantToComparedPropertyOrField()
+        {
+            Assert.IsTrue(Posts.AsQueryable().Query(t => t.Equal("ForeignKey", 1, QueryConvertStrategy.ConvertConstantToComparedPropertyOrField)).Any());
+            Assert.IsTrue(Posts.AsQueryable().Query(t => t.Equal("ForeignKey", "1", QueryConvertStrategy.ConvertConstantToComparedPropertyOrField)).Any());
+            Assert.IsTrue(Posts.AsQueryable().Query(t => t.Equal("Id", 1, QueryConvertStrategy.ConvertConstantToComparedPropertyOrField)).Any());
+            Assert.IsTrue(Posts.AsQueryable().Query(t => t.Equal("Id", "1", QueryConvertStrategy.ConvertConstantToComparedPropertyOrField)).Any());
+        }
+    }
+}

PoweredSoft.DynamicLinq.Test/PoweredSoft.DynamicLinq.Test.csproj

@@ -61,6 +61,7 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="ComplexQueriesTests.cs" />
+    <Compile Include="ConstantTests.cs" />
     <Compile Include="Helpers\QueryableAssert.cs" />
     <Compile Include="ShortcutTests.cs" />
     <Compile Include="SimpleQueriesTest.cs" />

PoweredSoft.DynamicLinq/Constants.cs

@@ -23,7 +23,8 @@ namespace PoweredSoft.DynamicLinq
     public enum QueryConvertStrategy
     {
         LeaveAsIs,
-        ConvertConstantToComparedPropertyOrField
+        ConvertConstantToComparedPropertyOrField,
+        SpecifyType
     }
 
     public enum QueryCollectionHandling

PoweredSoft.DynamicLinq/Helpers/QueryableHelpers.cs

@@ -81,7 +81,7 @@ namespace PoweredSoft.DynamicLinq.Helpers
 
             // attempt a conversion.
             object convertedValue = TypeHelpers.ConvertFrom(memberType, value);
-            return Expression.Constant(convertedValue);
+            return Expression.Constant(convertedValue, memberType);
         }
 
         public static ConstantExpression ResolveConstant(Expression member, object value, QueryConvertStrategy convertStrategy)
@@ -89,6 +89,9 @@ namespace PoweredSoft.DynamicLinq.Helpers
             if (convertStrategy == QueryConvertStrategy.LeaveAsIs)
                 return Expression.Constant(value);
 
+            if (convertStrategy == QueryConvertStrategy.SpecifyType)
+                return Expression.Constant(value, member.Type);
+
             if (convertStrategy == QueryConvertStrategy.ConvertConstantToComparedPropertyOrField)
                 return QueryableHelpers.GetConstantSameAsLeftOperator(member, value);