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PODapper.NET multi mapping TSecond Deserializer is null
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  1. PODapper.NET multi mapping TSecond Deserializer is null
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    copied!<p>I'm trying to perform a very standard multi mapping query using Dapper, and I'm getting the following error. I also get another error occasionally when this seems to work, but I'm unable to reproduce it at the moment. I'll append it to this post if/when the first problem is solved.</p> <p>Here is the query code:</p> <pre><code> const string storedProc = "dbo.GetStopsForRouteID"; var stops = conn.Query&lt;RouteStop, MapLocation, RouteStop&gt;( storedProc, (stop, loc) =&gt; { stop.Location = loc; return stop; }, new { RouteID = routeId }, commandType: CommandType.StoredProcedure); </code></pre> <p>In Dapper.cs on line 498:</p> <pre><code>var deserializer2 = (Func&lt;IDataReader, TSecond&gt;)info.OtherDeserializers[0]; </code></pre> <p>info.OtherDeserializers is null which causes a NullReferenceException.</p> <p>This is the guts of the stored procedure:</p> <pre><code>SELECT RouteStops.StopID, RouteStops.Name, RouteStops.Description, RouteStops.IsInbound, RouteStops.Location.Lat as Latitude, RouteStops.Location.Long as Longitude FROM dbo.Routes INNER JOIN dbo.StopsOnRoute ON Routes.RouteID = StopsOnRoute.RouteID INNER JOIN dbo.RouteStops ON StopsOnRoute.StopID = RouteStops.StopID WHERE Routes.RouteID = @RouteID ORDER BY StopsOnRoute.SequenceNumber </code></pre> <p>I've had an extensive look at the dapper code but I can't find anything that seems out of place other than that TFirst's deserialiser isn't null, but TSecond's is. Could there be a problem when it creates TSecond's deserializer that leaves it as null?</p> <p>Here are the types:</p> <pre><code>public class MapLocation { public double Latitude { get; set; } public double Longitude { get; set; } } public class RouteStop { public int StopID { get; set; } public string Name { get; set; } public string Description { get; set; } public bool IsInbound { get; set; } public MapLocation Location { get; set; } } </code></pre>
 

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