Convert enum values to workaround Npgsql > 4.0 strict type checking. Fixes #105

Author: rwasef1830

src/EntityFramework6.Npgsql/NpgsqlServices.cs

@@ -32,6 +32,7 @@
 using Npgsql.SqlGenerators;
 using DbConnection = System.Data.Common.DbConnection;
 using DbCommand = System.Data.Common.DbCommand;
+using System.Data.Common;
 
 #pragma warning disable CS1591 // Missing XML comment for publicly visible type or member
 
@@ -73,6 +74,26 @@ internal DbCommand CreateDbCommand(Version serverVersion, DbCommandTree commandT
             return command;
         }
 
+        protected override void SetDbParameterValue(DbParameter parameter, TypeUsage parameterType, object value)
+        {
+            base.SetDbParameterValue(parameter, parameterType, value);
+            ConvertValueToNumericIfEnum(parameter);
+        }
+
+        // Npgsql > 4.0 does strict type checks on integral values and fails with enums passed with numeric DbType.
+        static void ConvertValueToNumericIfEnum(DbParameter parameter)
+        {
+            var parameterValueObjectType = parameter.Value.GetType();
+
+            if (!parameterValueObjectType.IsEnum)
+            {
+                return;
+            }
+
+            var underlyingType = Enum.GetUnderlyingType(parameterValueObjectType);
+            parameter.Value = Convert.ChangeType(parameter.Value, underlyingType);
+        }
+
         internal void TranslateCommandTree(Version serverVersion, DbCommandTree commandTree, DbCommand command, bool createParametersForNonSelect = true)
         {
             SqlBaseGenerator sqlGenerator;

test/EntityFramework6.Npgsql.Tests/EntityFrameworkBasicTests.cs

@@ -847,5 +847,70 @@ public void Test_string_multiple_null_propagation()
                     query.ToString());
             }
         }
+
+        [Test]
+        public void Test_enum()
+        {
+            using (var context = new BloggingContext(ConnectionString))
+            {
+                context.Database.Log = Console.Out.WriteLine;
+
+                context.ClrEnumEntities.Add(
+                    new ClrEnumEntity
+                    {
+                        TestByte = TestByteEnum.Bar,
+                        TestShort = TestShortEnum.Bar,
+                        TestInt = TestIntEnum.Bar,
+                        TestLong = TestLongEnum.Bar
+                    });
+                context.SaveChanges();
+
+                var query = context.ClrEnumEntities.Where(
+                    x => x.TestByte == TestByteEnum.Bar
+                         && x.TestShort == TestShortEnum.Bar
+                         && x.TestInt == TestIntEnum.Bar
+                         && x.TestLong == TestLongEnum.Bar);
+
+                var result = query.First();
+                Assert.That(result.TestByte, Is.EqualTo(TestByteEnum.Bar));
+                Assert.That(result.TestShort, Is.EqualTo(TestShortEnum.Bar));
+                Assert.That(result.TestInt, Is.EqualTo(TestIntEnum.Bar));
+                Assert.That(result.TestLong, Is.EqualTo(TestLongEnum.Bar));
+            }
+        }
+
+        [Test]
+        public void Test_enum_composite_key()
+        {
+            using (var context = new BloggingContext(ConnectionString))
+            {
+                context.Database.Log = Console.Out.WriteLine;
+
+                context.ClrEnumCompositeKeyEntities.Add(
+                    new ClrEnumCompositeKeyEntity
+                    {
+                        TestByte = TestByteEnum.Bar,
+                        TestShort = TestShortEnum.Bar,
+                        TestInt = TestIntEnum.Bar,
+                        TestLong = TestLongEnum.Bar
+                    });
+                context.SaveChanges();
+            }
+
+            using (var context = new BloggingContext(ConnectionString))
+            { 
+                var result = context.ClrEnumCompositeKeyEntities.Find(
+                        TestByteEnum.Bar,
+                        TestShortEnum.Bar,
+                        TestIntEnum.Bar,
+                        TestLongEnum.Bar);
+
+                Assert.That(result, Is.Not.Null);
+                Assert.That(result.TestByte, Is.EqualTo(TestByteEnum.Bar));
+                Assert.That(result.TestShort, Is.EqualTo(TestShortEnum.Bar));
+                Assert.That(result.TestInt, Is.EqualTo(TestIntEnum.Bar));
+                Assert.That(result.TestLong, Is.EqualTo(TestLongEnum.Bar));
+            }
+        }
     }
 }

test/EntityFramework6.Npgsql.Tests/Support/EntityFrameworkTestBase.cs

@@ -25,6 +25,7 @@
 using NUnit.Framework;
 using System;
 using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
 using System.Data.Common;
 using System.Data.Entity;
 using System.Linq;
@@ -102,6 +103,54 @@ public class Post
         public virtual Blog Blog { get; set; }
     }
 
+    public class ClrEnumEntity
+    {
+        public int Id { get; set; }
+        public TestByteEnum TestByte { get; set; }
+        public TestShortEnum TestShort { get; set; }
+        public TestIntEnum TestInt { get; set; }
+        public TestLongEnum TestLong { get; set; }
+    }
+
+    public class ClrEnumCompositeKeyEntity
+    {
+        [Key, Column(Order = 1)]
+        public TestByteEnum TestByte { get; set; }
+
+        [Key, Column(Order = 2)]
+        public TestShortEnum TestShort { get; set; }
+
+        [Key, Column(Order = 3)]
+        public TestIntEnum TestInt { get; set; }
+
+        [Key, Column(Order = 4)]
+        public TestLongEnum TestLong { get; set; }
+    }
+
+    public enum TestByteEnum : byte
+    {
+        Foo = 0,
+        Bar = 1
+    }
+
+    public enum TestShortEnum : short
+    {
+        Foo = 0,
+        Bar = 1
+    }
+
+    public enum TestIntEnum
+    {
+        Foo = 0,
+        Bar = 1
+    }
+
+    public enum TestLongEnum : long
+    {
+        Foo = 0,
+        Bar = 1
+    }
+
     public class NoColumnsEntity
     {
         public int Id { get; set; }
@@ -131,6 +180,8 @@ public BloggingContext(string connection)
         public DbSet<Blog> Blogs { get; set; }
         public DbSet<Post> Posts { get; set; }
         public DbSet<NoColumnsEntity> NoColumnsEntities { get; set; }
+        public DbSet<ClrEnumEntity> ClrEnumEntities { get; set; }
+        public DbSet<ClrEnumCompositeKeyEntity> ClrEnumCompositeKeyEntities { get; set; }
         public DbSet<User> Users { get; set; }
         public DbSet<Editor> Editors { get; set; }
         public DbSet<Administrator> Administrators { get; set; }
@@ -164,6 +215,8 @@ private static DbCompiledModel CreateModel(NpgsqlConnection connection)
             dbModelBuilder.Entity<Blog>();
             dbModelBuilder.Entity<Post>();
             dbModelBuilder.Entity<NoColumnsEntity>();
+            dbModelBuilder.Entity<ClrEnumEntity>();
+            dbModelBuilder.Entity<ClrEnumCompositeKeyEntity>();
             dbModelBuilder.Entity<User>();
             dbModelBuilder.Entity<Editor>();
             dbModelBuilder.Entity<Administrator>();