diff --git a/DynamORM.Tests/Modify/ParserTests.cs b/DynamORM.Tests/Modify/ParserTests.cs
index 5603885..72aef75 100644
--- a/DynamORM.Tests/Modify/ParserTests.cs
+++ b/DynamORM.Tests/Modify/ParserTests.cs
@@ -68,5 +68,58 @@ namespace DynamORM.Tests.Modify
             Assert.AreEqual(string.Format(@"INSERT INTO ""Users"" (""Code"", ""Name"", ""IsAdmin"") VALUES ({0})",
                 string.Join(", ", cmd.Parameters.Keys.Select(p => string.Format("[${0}]", p)))), cmd.CommandText());
         }
+
+        /// <summary>
+        /// Tests the insert with sub query.
+        /// </summary>
+        [Test]
+        public void TestInsertSubQuery()
+        {
+            var cmd = new DynamicInsertQueryBuilder(Database, "Users");
+
+            cmd.Insert(x => x.Code = "001", x => x.Name = "Admin", x => x.IsAdmin = x(cmd
+                .SubQuery(a => a.AccessRights.As(a.a))
+                .Select(a => a.IsAdmin)
+                .Where(a => a.User_Id == "001")));
+
+            Assert.AreEqual(string.Format(@"INSERT INTO ""Users"" (""Code"", ""Name"", ""IsAdmin"") VALUES ({0}, (SELECT a.""IsAdmin"" FROM ""AccessRights"" AS a WHERE (a.""User_Id"" = [${1}])))",
+                string.Join(", ", cmd.Parameters.Keys.Take(2).Select(p => string.Format("[${0}]", p))), cmd.Parameters.Keys.Last()), cmd.CommandText());
+        }
+
+        /// <summary>
+        /// Tests the basic insert using object.
+        /// </summary>
+        [Test]
+        public void TestBasicInsertObject()
+        {
+            var cmd = new DynamicInsertQueryBuilder(Database, "Users");
+
+            cmd.Insert(x => new { Code = "001", Name = "Admin", IsAdmin = 1 });
+
+            Assert.AreEqual(string.Format(@"INSERT INTO ""Users"" (""Code"", ""Name"", ""IsAdmin"") VALUES ({0})",
+                string.Join(", ", cmd.Parameters.Keys.Select(p => string.Format("[${0}]", p)))), cmd.CommandText());
+        }
+
+        /// <summary>
+        /// Tests the insert using object with sub query.
+        /// </summary>
+        [Test]
+        public void TestInsertSubQueryObject()
+        {
+            var cmd = new DynamicInsertQueryBuilder(Database, "Users");
+
+            cmd.Insert(x => new
+            {
+                Code = "001",
+                Name = "Admin",
+                IsAdmin = x(cmd
+                    .SubQuery(a => a.AccessRights.As(a.a))
+                    .Select(a => a.IsAdmin)
+                    .Where(a => a.User_Id == "001"))
+            });
+
+            Assert.AreEqual(string.Format(@"INSERT INTO ""Users"" (""Code"", ""Name"", ""IsAdmin"") VALUES ({0}, (SELECT a.""IsAdmin"" FROM ""AccessRights"" AS a WHERE (a.""User_Id"" = [${1}])))",
+                string.Join(", ", cmd.Parameters.Keys.Take(2).Select(p => string.Format("[${0}]", p))), cmd.Parameters.Keys.Last()), cmd.CommandText());
+        }
     }
 }
\ No newline at end of file
diff --git a/DynamORM.Tests/Select/DynamicAccessTests.cs b/DynamORM.Tests/Select/DynamicAccessTests.cs
index 223e569..371816f 100644
--- a/DynamORM.Tests/Select/DynamicAccessTests.cs
+++ b/DynamORM.Tests/Select/DynamicAccessTests.cs
@@ -436,6 +436,29 @@ namespace DynamORM.Tests.Select
             Assert.AreEqual(exp.last, o.last);
         }
 
+        /// <summary>Test dynamic duplicate column name ocurrance.</summary>
+        [Test]
+        public void TestDuplicateColumnNameException()
+        {
+            Assert.Throws<ArgumentException>(() => GetTestBuilder()
+                .Where(x => x.id == 19)
+                .Select(x => new { id = x.id, first = x.first, last = x.last })
+                .Select(x => x.last.As(x.first)) // Make last be first
+                .Execute()
+                .First());
+        }
+
+        [Test]
+        public void TestEmptyColumnName()
+        {
+            var v = GetTestBuilder()
+                .Select(x => x.first, x => x.Count(x.first))
+                .GroupBy(x => x.first)
+                .OrderBy(x => x.Desc(2))
+                .Execute()
+                .ToList();
+        }
+
         #endregion Select
 
         #region Where
diff --git a/DynamORM.Tests/Select/ParserTests.cs b/DynamORM.Tests/Select/ParserTests.cs
index 7de7914..2d2f4e1 100644
--- a/DynamORM.Tests/Select/ParserTests.cs
+++ b/DynamORM.Tests/Select/ParserTests.cs
@@ -482,6 +482,20 @@ namespace DynamORM.Tests.Select
             Assert.AreEqual("SELECT \"dbo\".\"Users\".\"UserName\" AS \"Name\" FROM \"dbo\".\"Users\"", cmd.CommandText());
         }
 
+        /// <summary>
+        /// Tests select field with alias.
+        /// </summary>
+        [Test]
+        public void TestSelectFieldAlias3()
+        {
+            IDynamicSelectQueryBuilder cmd = new DynamicSelectQueryBuilder(Database);
+
+            cmd.From(u => u.dbo.Users.As(u.u))
+                .Select(u => u.UserName.As(u.Name));
+
+            Assert.AreEqual("SELECT u.\"UserName\" AS \"Name\" FROM \"dbo\".\"Users\" AS u", cmd.CommandText());
+        }
+
         /// <summary>
         /// Tests select aggregate field with alias (Sum).
         /// </summary>
diff --git a/DynamORM.Tests/Select/TypedAccessTests.cs b/DynamORM.Tests/Select/TypedAccessTests.cs
index 333c74e..1fcfb1b 100644
--- a/DynamORM.Tests/Select/TypedAccessTests.cs
+++ b/DynamORM.Tests/Select/TypedAccessTests.cs
@@ -38,7 +38,7 @@ namespace DynamORM.Tests.Select
     /// <summary>Test typed ORM.</summary>
     /// <typeparam name="T">Type to test.</typeparam>
     [TestFixture(typeof(users))]
-    public class TypedAccessTests<T> : TestsBase
+    public class TypedAccessTests<T> : TestsBase where T : class
     {
         /// <summary>Setup test parameters.</summary>
         [TestFixtureSetUp]
@@ -97,6 +97,18 @@ namespace DynamORM.Tests.Select
             Assert.AreEqual(200, list.Count);
         }
 
+        /// <summary>Test load all rows into mapped list alternate way.</summary>
+        [Test]
+        public virtual void TestTypedGetAll3()
+        {
+            var list = GetTestBuilder()
+                .From(x => x(typeof(T)).As(x.t))
+                .Execute<T>()
+                .ToList();
+
+            Assert.AreEqual(200, list.Count);
+        }
+
         /// <summary>Test unknown op.</summary>
         [Test]
         public virtual void TestTypedUnknownOperation()
diff --git a/DynamORM/Builders/IDynamicSelectQueryBuilder.cs b/DynamORM/Builders/IDynamicSelectQueryBuilder.cs
index a4935e8..b8194ba 100644
--- a/DynamORM/Builders/IDynamicSelectQueryBuilder.cs
+++ b/DynamORM/Builders/IDynamicSelectQueryBuilder.cs
@@ -5,12 +5,17 @@ namespace DynamORM.Builders
 {
     /// <summary>Dynamic select query builder interface.</summary>
     /// <remarks>This interface it publically available. Implementation should be hidden.</remarks>
-    public interface IDynamicSelectQueryBuilder : IDynamicQueryBuilder, IEnumerable<object>
+    public interface IDynamicSelectQueryBuilder : IDynamicQueryBuilder ////, IEnumerable<object>
     {
         /// <summary>Execute this builder.</summary>
         /// <returns>Enumerator of objects expanded from query.</returns>
         IEnumerable<dynamic> Execute();
 
+        /// <summary>Execute this builder and map to given type.</summary>
+        /// <typeparam name="T">Type of object to map on.</typeparam>
+        /// <returns>Enumerator of objects expanded from query.</returns>
+        IEnumerable<T> Execute<T>() where T : class;
+
         /// <summary>Returns a single result.</summary>
         /// <returns>Result of a query.</returns>
         object Scalar();
diff --git a/DynamORM/DynamicExtensions.cs b/DynamORM/DynamicExtensions.cs
index 5b61315..5487b65 100644
--- a/DynamORM/DynamicExtensions.cs
+++ b/DynamORM/DynamicExtensions.cs
@@ -913,7 +913,15 @@ namespace DynamORM
 
             int c = r.FieldCount;
             for (int i = 0; i < c; i++)
-                d.Add(r.GetName(i), r.IsDBNull(i) ? null : r[i]);
+                try
+                {
+                    d.Add(r.GetName(i), r.IsDBNull(i) ? null : r[i]);
+                }
+                catch (ArgumentException argex)
+                {
+                    throw new ArgumentException(
+                        string.Format("Field '{0}' is defined more than once in a query.", r.GetName(i)), "Column name or alias", argex);
+                }
 
             return e;
         }
diff --git a/DynamORM/DynamicTable.cs b/DynamORM/DynamicTable.cs
index a11b05b..6ded5a4 100644
--- a/DynamORM/DynamicTable.cs
+++ b/DynamORM/DynamicTable.cs
@@ -31,6 +31,7 @@ using System.Collections.Generic;
 using System.Data;
 using System.Dynamic;
 using System.Linq;
+using System.Text;
 using DynamORM.Builders;
 using DynamORM.Builders.Extensions;
 using DynamORM.Builders.Implementation;
@@ -340,14 +341,30 @@ namespace DynamORM
         {
             using (var con = Database.Open())
             using (var cmd = con.CreateCommand())
-            {
-                using (var rdr = cmd
-                    .SetCommand(sql)
-                    .AddParameters(Database, args)
-                    .ExecuteReader())
-                    while (rdr.Read())
-                        yield return rdr.RowToDynamic();
-            }
+            using (var rdr = cmd
+                .SetCommand(sql, args)
+                .ExecuteReader())
+                while (rdr.Read())
+                {
+                    dynamic val = null;
+
+                    // Work around to avoid yield being in try...catch block:
+                    // http://stackoverflow.com/questions/346365/why-cant-yield-return-appear-inside-a-try-block-with-a-catch
+                    try
+                    {
+                        val = rdr.RowToDynamic();
+                    }
+                    catch (ArgumentException argex)
+                    {
+                        var sb = new StringBuilder();
+                        cmd.Dump(sb);
+
+                        throw new ArgumentException(string.Format("{0}{1}{2}", argex.Message, Environment.NewLine, sb),
+                            argex.InnerException.NullOr(a => a, argex));
+                    }
+
+                    yield return val;
+                }
         }
 
         /// <summary>Enumerate the reader and yield the result.</summary>
@@ -357,13 +374,30 @@ namespace DynamORM
         {
             using (var con = Database.Open())
             using (var cmd = con.CreateCommand())
-            {
-                using (var rdr = cmd
-                    .SetCommand(builder)
-                    .ExecuteReader())
-                    while (rdr.Read())
-                        yield return rdr.RowToDynamic();
-            }
+            using (var rdr = cmd
+                .SetCommand(builder)
+                .ExecuteReader())
+                while (rdr.Read())
+                {
+                    dynamic val = null;
+
+                    // Work around to avoid yield being in try...catch block:
+                    // http://stackoverflow.com/questions/346365/why-cant-yield-return-appear-inside-a-try-block-with-a-catch
+                    try
+                    {
+                        val = rdr.RowToDynamic();
+                    }
+                    catch (ArgumentException argex)
+                    {
+                        var sb = new StringBuilder();
+                        cmd.Dump(sb);
+
+                        throw new ArgumentException(string.Format("{0}{1}{2}", argex.Message, Environment.NewLine, sb),
+                            argex.InnerException.NullOr(a => a, argex));
+                    }
+
+                    yield return val;
+                }
         }
 
         /// <summary>Create new <see cref="DynamicSelectQueryBuilder"/>.</summary>