For my SQL geography computed column, I used the same as from your trigger ( [geography]::STGeomFromWKB([CenterPointBytes],(4326)) ).

As an example, here is my GeoLat property (in VB.Net):

Public Property GeoLat As Double?
Get
If CenterPointBytes Is Nothing Then
Return New Nullable(Of Double)(Nothing)
Else
Return Math.Round(SqlGeography.STGeomFromWKB(New SqlBytes(CenterPointBytes), 4326).Lat.Value, 5)
End If
End Get
Set(ByVal value As Double?)
If value.HasValue AndAlso value 0 Then
Dim oldGeo As SqlGeography = SqlGeography.STGeomFromWKB(New SqlBytes(CenterPointBytes), 4326)
If CenterPointBytes Is Nothing OrElse oldGeo.IsNull OrElse oldGeo.Long.IsNull Then
Dim newGeo As SqlGeography = SqlGeography.STPointFromText(New SqlChars(New SqlString(String.Format(“POINT({0} {1})”, 0, value))), 4326)
CenterPointBytes = newGeo.STAsBinary().Value
Else
Dim sqlGeo As SqlGeography = SqlGeography.STPointFromText(New SqlChars(New SqlString(String.Format(“POINT({0} {1})”, oldGeo.Long, value))), 4326)
CenterPointBytes = sqlGeo.STAsBinary().Value
End If
End If
End Set
End Property

What matters is properly EdmFunction “filled” attribute and you have to have this SP imported in model, of course.

I’m trying to get it to work, but my [EdmFunction] isn’t happy.

I don’t understand … it looks like Distance() is an extension method, but it’s internal? My compiler doesn’t like that. I made it public and put it in a public static class and it compiles, but I get:

System.NotSupportedException: The specified method ‘Int32 Distance(Byte[], Byte[])’ on the type ‘MyApp.DistanceExtension’ cannot be translated into a LINQ to Entities store expression.

My database has the function and everything else …

Thanks for the solution. I didn’t know we could do that in EF. It’s good to know about the functions.

In this case, to take advantage of indexes you could just write the query using dynamica SQL.
context.CreateQuery(“SELECT bla from X where …”, param1,param2);
This is probably not as elegant, but in this case I would go for the performant version.

Also I know that it’s hard to support and MS might be thinking of 3rd party DBs, but NHibernate has a really good support for UserTypes that works well accross different DBs, so well that they even support SqlSpatial and queries on top of it

And BTW OT the MS SQL spatial data support is a good average, nothing super ultra great. At least IMO.

For anyone doing serious spatial work, I’ve concluded that the Entity Framework is a complete load of bull. I’ve exhaustively tested all the proposed work-arounds.

SQL Server spatial performs great. But the Entity Framework (for spatial) is a dead-end, and will remain a dead-end until MS fixes it.