Dapper and anonymous Types

Question

Is it possible to use anonymous types with Dapper?

I can see how you can use dynamic i.e.

connection.Query<dynamic>(blah, blah, blah)  

is it then possible to do a

.Select(p=> new { A, B ,C })  

or some variation of that afterwards?

Edit

I thought I'd show you how I am using Dapper at the moment. I tend to cache (using an InMemoryCache) data so I just do one big query at the beginning (which is super quick using Dapper) then I use Linq to sort it all out in my Repository.

using System; using System.Collections.Generic; using System.Configuration; using System.Data.Common; using System.Linq; using Dapper;  namespace SomeNamespace.Data { public class DapperDataContext : IDisposable {     private readonly string _connectionString;     private readonly DbProviderFactory _provider;     private readonly string _providerName;      public DapperDataContext()     {         const string connectionStringName = " DataContextConnectionString";         _connectionString = ConfigurationManager.ConnectionStrings[connectionStringName].ConnectionString;         _providerName = ConfigurationManager.ConnectionStrings[connectionStringName].ProviderName;         _provider = DbProviderFactories.GetFactory(_providerName);     }      public IEnumerable<MyDataView> MyData1 { get; private set; }     public IEnumerable<MyDataView> MyData2 { get; private set; }      protected string SqlSelectMyTable1Query     {         get         {             return @"SELECT Id, A, B, C from table1Name";         }     }      protected string SqlSelectMyTable2Query {     get     {     return @"SELECT Id, A, B, C from table2Name";     }     }      public void Dispose()     {     }      public void Refresh()     {         using (var connection = _provider.CreateConnection())         {             // blow up if null             connection.ConnectionString = _connectionString;             connection.Open();              var sql = String.Join(" ",                             new[]                                 {                                     SqlSelectMyTable1Query,                                     SqlSelectMyTable2Query                                 });              using (var multi = connection.QueryMultiple(sql))             {                 MyData1 = multi.Read<MyDataView>().ToList();                 MyData2 = multi.Read<MyDataView>().ToList();             }         }     }      public class MyDataView     {         public long Id { get; set; }         public string A { get; set; }         public string B { get; set; }         public string C { get; set; }     }       } } 

The InMemoryCache looks like this

namespace Libs.Web { public class InMemoryCache : ICacheService {     #region ICacheService Members      public T Get<T>(string cacheId, Func<T> getItemCallback) where T : class     {         var item = HttpRuntime.Cache.Get(cacheId) as T;         if (item == null)         {             item = getItemCallback();             HttpContext.Current.Cache.Insert(cacheId, item);         }         return item;     }      public void Clear(string cacheId)     {         HttpContext.Current.Cache.Remove(cacheId);     }      #endregion }  public interface ICacheService {     T Get<T>(string cacheId, Func<T> getItemCallback) where T : class;     void Clear(string cacheId); } } 

Answer 1

Is it possible to use anonymous types with Dapper?

Sure see the non-generic Query override, it return a dynamic IDictionary<string, object> this object is an expando that can either be cast or accessed with dot notation.

Eg:

var v = connection.Query("select 1 as a, 2 as b").First();  Console.Write("{0} {1}",v.a, v.b) // prints: 1 2 

is it then possible to do a .Select

Sure, you get an IEnumerable<dynamic> ... you can run anything you want on that.