C# Invalid SRID when inserting binary data

Question

Hello , 

I'm trying to insert some polygons in my DB  using nHibernate and i have received the following error : 

A .NET Framework error occurred during execution of user-defined routine or aggregate "geography": System.ArgumentException: 24204: The spatial reference identifier (SRID) is not valid. The specified SRID must match one of the supported SRIDs displayed in the sys.spatial_reference_systems catalog view. System.ArgumentException: at Microsoft.SqlServer.Types.SqlGeography.set_Srid(Int32 value) at Microsoft.SqlServer.Types.SqlGeography.Read(BinaryReader r) at SqlGeography::.DeserializeValidate(IntPtr , Int32 , CClrLobContext* ) . The statement has been terminated.

but i have entered a SRID = 4326;

I'm using a

SqlGeographyBuilder();

to build a polygon (rectangle) :

                    double left = Math.Min(NELng, SWLng);
                    double right = Math.Max(NELng, SWLng);

                    double bottom = Math.Min(NELat, SWLat);
                    double top = Math.Max(NELat, SWLat);

                    SqlGeographyBuilder builder = new SqlGeographyBuilder();

                    builder.SetSrid(LocationUtils.SRID);
                    builder.BeginGeography(OpenGisGeographyType.Polygon);
                 
                    builder.BeginFigure(top, left);

                    builder.AddLine(bottom, left);
                    builder.AddLine(bottom, right);
                    builder.AddLine(top, right);
                    builder.AddLine(top, left);
                    builder.EndFigure();
                    builder.EndGeography();

what am I doing wrong ? 

Answer 1

There's nothing I can see obviously wrong with your code... are you sure that LocationUtils.SRID is an int value 4326?

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twitter: @alastaira blog: http://alastaira.wordpress.com/

Answer 2

My bad , i wasn't using NHibernate , but Linq2Sql .... 

Can someone show me a sample on how to insert geo data with linq2sql or any other way ?

Thanks! 

Answer 3

The latest version of the Entity Framework 5 (currently in Beta) is the only one to provide native support to spatial datatypes. But, these are only available if you're targetting a .NET 4.5 application. There's an example using LINQ at http://msdn.microsoft.com/en-us/hh859721

If you're using an older version of Linq2SQL or targetting .NET <= 4.0 then you'll have to use a workaround, such as that described at http://blogs.u2u.be/diederik/post/2010/01/03/The-Missing-Linq-to-SQL-Spatial.aspx

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twitter: @alastaira blog: http://alastaira.wordpress.com/