Subsonic 3 – Object of type ‘System.Byte[]’ cannot be converted to type ‘System.String’

With a little bit dotnet magic it is possible without patching the subsonic code.

1. Create a new class SubsonicSqlQueryExtensionMethods and drop this code:

   using System;
   using System.Collections.Generic;
   using System.Linq;
   using System.Text;
   
   using SubSonic;
   
   namespace MyUtil.ExtensionMethods
   {
       public static class SubSonicSqlQueryExtensionMethods
       {
           public static List<String> ExecuteTypedList(this SqlQuery qry)
           {
               List<String> list = new List<String>();
               foreach (System.Data.DataRow row in qry.ExecuteDataSet().Tables[0].Rows)
               {
                    list.Add((String)row[0]);
               }
               return list;
           }
       }
   }
   

Now add a reference to MyUtil.ExtensionMethods to your class:

    using MyUtil.ExtensionMethods;

And finally this works:

    List<String> result = DB.Select(User.Columns.Name).From<User>().ExecuteTypedList();

Please note that the above extension method overloads the ExecuteTypedList() method with no type-argument (unfortunately this snippet requires dotnet 3.5, but for me it works)

Just found the solution. A user already reported this bug 33 weeks ago and posted a fix at: http://blog.wekeroad.com/subsonic/subsonic-3-0-repository-template-update/

Has to do with generation of tinyint datatype.