Dapper SqlGeography error

当我尝试选择一个名为zones2的POCO时，Dapper出现错误。

public partial class ZONES2
{
    public int ID { get; set; }
    public SqlGeography LATLNG { get; set; }
}

此代码会产生错误。

  using (SqlConnection conn = new SqlConnection(connStr))
  {
     var zones = conn.Query<ZONES2>("select id,latlng from zones2");
  }

错误为：

System.Data.DataException was unhandled

HResult=-2146223087消息=分析列1时出错（latlng=POLYGON(（50.804687175845011-1.1351966857910156，50.803927780711625-1.1324286460876465，50.804531229637192-1.1276113986968994，50.804870242468276-1.1231803894042969，50.8037379299972-1.1219358444213867，50.80011705805952-1.1197042465209961，50.796767162631618-1.1166036128997803，50.793932448170736-1.1145973205566406，50.79183003693492-1.1151659488677979，50.7920199360792-1.1166250705718994，50.789123891025056-1.1191999912261963、50.790316143034808-1.1227444584776549、50.790744884457638-1.1259269714355469、50.791687612108106-1.127171516418457、50.793932448170736-1.1280298233032227、50.794217283709372-1.128898590240479、50.794786949579219-1.1292421817779541、50.795675343209147-1.1292743682861328、50.79740822452452452-1.12932578323452、50.797587705782-1.1320317979153444，50.797784362743926-1.1328577995300293、50.79778432743926-1.1339521408081055、50.79802269251892-1.135221529627079、50.799967877542073-1.1342954635620117、50.801562477015025-1.1342542270608647、50.804687175845011-1.1351966857910156、50.80468 7175845011-1.1351966857910156）-对象）来源=DapperStackTrace：在D:''Dev''Dapper dot-net''Dapper NET40''SqlMapper.cs:line 4153中的Dapper.SqlMapper.SthrowDataException（Exception ex，Int32索引，IDataReader读取器，对象值）位于Deserialize0c167990-8477-4066-b090-cd522cbf0768（IDataReader）在Dapper.SqlMapper.d_61 1.MoveNext() in D:'Dev'dapper-dot-net'Dapper NET40'SqlMapper.cs:line 1608 at System.Collections.Generic.List 1..ctor（IEnumerable 1 collection) at System.Linq.Enumerable.ToList[TSource](IEnumerable 1源）在D:''Dev''Dapper dot-net''Dapper NET40''SqlMapper.cs:line 1479中的Dapper.SqlMapper.Query[T]（IDbConnection cnn，String sql，Object param，IDbTransaction transaction，布尔缓冲，可为空的1 commandTimeout, Nullable 1 commandType）空间。c:''users''paul''Google Drive''Visual Studio 2015''spacespace''space''Program.cs:line 17中的Program.Main（String[]args）位于System.AppDomain_nExecuteAssembly（RuntimeAssembly程序集，String[]参数）位于System.AppDomain.ExecuteAssembly（String assemblyFile，Evidence assemblySecurity，String[]args）位于Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly（）位于System.Threading.ThreadHelper.ThreadStart_Context（对象状态）位于System.Threading.ExecutionContext.RunInternal（ExecutionContext ExecutionContext，ContextCallback回调，对象状态，布尔值preserveSyncCtx）在System.Threading.ExecutionContext.Run（ExecutionContext ExecutionContext，ContextCallback回调，Object state，Boolean preserveSyncCtx）在System.Threading.ExecutionContext.Run（ExecutionContext ExecutionContext，ContextCallback回调，对象状态）位于System.Threading.ThreadHelper.ThreadStart（）内部异常：HResult=-2147467262消息=[A]Microsoft.SqlServer.Types.SqlGeography无法强制转换为[B]Microsoft.SqlServer.Types.SqlGeography。类型A源自"Microsoft.SqlServer.Types，Version=10.0.0，Culture=neutral，PublicKeyToken=88945dcd8080cc91'，位于上下文"Default"中，位置为"C:''WINDOWS''assembly''GAC_MSIL''Microsoft.SqlServer.Types''10.0.0.0''__89845dcd8080cc91''Microsoft.SqlServer.Types.dll"。类型B源自"Microsoft.SqlServer.Types，Version=11.0.0.0，Culture=neutral，PublicKeyToken=89845dcd8080cc91'，位于上下文"Default"中，位置为"C:''WINDOWS''assembly''GAC_MSIL''Microsoft.SqlServer.Types''11.0.0.0__89845dcd 8080cc91 ''Microsoft.SqlServer.Types.dll"。Source=匿名托管的DynamicMethods程序集StackTrace：位于Deserialize0c167990-8477-4066-b090-cd522cbf0768（IDataReader）内部异常：

然而，当我尝试这个代码时，它运行正常。（N.B.动态类型）

     using (SqlConnection conn = new SqlConnection(connStr))
     {
         var zones = conn.Query<dynamic>("select id,latlng from zones2");
     }

我想知道为什么我在第一个代码中出现错误？