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    <p>This can be done, as mentioned, with the help of Reflection Emit and a helper class I've included below. The code below is a work in progress, so take it for what it's worth... 'it works on my box'. The SelectDynamic method class should be tossed in a static extension method class.</p> <p>As expected, you won't get any Intellisense since the type isn't created until runtime. Works good on late-bound data controls.</p> <pre><code>public static IQueryable SelectDynamic(this IQueryable source, IEnumerable&lt;string&gt; fieldNames) { Dictionary&lt;string, PropertyInfo&gt; sourceProperties = fieldNames.ToDictionary(name =&gt; name, name =&gt; source.ElementType.GetProperty(name)); Type dynamicType = LinqRuntimeTypeBuilder.GetDynamicType(sourceProperties.Values); ParameterExpression sourceItem = Expression.Parameter(source.ElementType, "t"); IEnumerable&lt;MemberBinding&gt; bindings = dynamicType.GetFields().Select(p =&gt; Expression.Bind(p, Expression.Property(sourceItem, sourceProperties[p.Name]))).OfType&lt;MemberBinding&gt;(); Expression selector = Expression.Lambda(Expression.MemberInit( Expression.New(dynamicType.GetConstructor(Type.EmptyTypes)), bindings), sourceItem); return source.Provider.CreateQuery(Expression.Call(typeof(Queryable), "Select", new Type[] { source.ElementType, dynamicType }, Expression.Constant(source), selector)); } public static class LinqRuntimeTypeBuilder { private static readonly ILog log = LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType); private static AssemblyName assemblyName = new AssemblyName() { Name = "DynamicLinqTypes" }; private static ModuleBuilder moduleBuilder = null; private static Dictionary&lt;string, Type&gt; builtTypes = new Dictionary&lt;string, Type&gt;(); static LinqRuntimeTypeBuilder() { moduleBuilder = Thread.GetDomain().DefineDynamicAssembly(assemblyName, AssemblyBuilderAccess.Run).DefineDynamicModule(assemblyName.Name); } private static string GetTypeKey(Dictionary&lt;string, Type&gt; fields) { //TODO: optimize the type caching -- if fields are simply reordered, that doesn't mean that they're actually different types, so this needs to be smarter string key = string.Empty; foreach (var field in fields) key += field.Key + ";" + field.Value.Name + ";"; return key; } public static Type GetDynamicType(Dictionary&lt;string, Type&gt; fields) { if (null == fields) throw new ArgumentNullException("fields"); if (0 == fields.Count) throw new ArgumentOutOfRangeException("fields", "fields must have at least 1 field definition"); try { Monitor.Enter(builtTypes); string className = GetTypeKey(fields); if (builtTypes.ContainsKey(className)) return builtTypes[className]; TypeBuilder typeBuilder = moduleBuilder.DefineType(className, TypeAttributes.Public | TypeAttributes.Class | TypeAttributes.Serializable); foreach (var field in fields) typeBuilder.DefineField(field.Key, field.Value, FieldAttributes.Public); builtTypes[className] = typeBuilder.CreateType(); return builtTypes[className]; } catch (Exception ex) { log.Error(ex); } finally { Monitor.Exit(builtTypes); } return null; } private static string GetTypeKey(IEnumerable&lt;PropertyInfo&gt; fields) { return GetTypeKey(fields.ToDictionary(f =&gt; f.Name, f =&gt; f.PropertyType)); } public static Type GetDynamicType(IEnumerable&lt;PropertyInfo&gt; fields) { return GetDynamicType(fields.ToDictionary(f =&gt; f.Name, f =&gt; f.PropertyType)); } } </code></pre>
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    1. POHow to create LINQ Expression Tree to select an anonymous type
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    1. USBeakie
    1. USEthan J. Brown
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    1. POHow to create LINQ Expression Tree to select an anonymous type
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    1. COwonderful, didn't know creating a type at runtime was that easy!thanks!
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      1. USmCasamento
    2. COGood but "Cannot serialize interface System.Linq.IQueryable"
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      1. USDavut Gürbüz
    3. COYou can put OrderBy in your //TODO for optimization and its done.
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      1. USAkash Kava
 

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