{"id":361,"date":"2012-07-11T17:03:00","date_gmt":"2012-07-11T17:03:00","guid":{"rendered":"https:\/\/staging.infragistics.com\/blogs\/?p=361"},"modified":"2025-02-26T12:27:10","modified_gmt":"2025-02-26T12:27:10","slug":"asp-net-mvc-with-sql-server","status":"publish","type":"post","link":"https:\/\/www.infragistics.com\/blogs\/asp-net-mvc-with-sql-server","title":{"rendered":"Using Spatial Data in ASP.Net MVC with SQL Server"},"content":{"rendered":"\n

CodeProject<\/a>Many developers have been asking since the release of SQL 2008 for support of Spatial data types in the Entity Framework. It was a dream for the Microsoft ORM users to create .NET business applications quickly, using spatial data.  In May of this year the release candidate for Entity Framework 5 (EF5) was announced.This version has increased performance when compared to earlier EF version and also has support for spatial types. The Spatial functionality in EF5 requires .NET 4.5.<\/p>\n\n\n\n

The Spatial functionality in EF5 requires .NET 4.5. This means you will need Visual Studios 2012 installed. You can download the release candidate for VS 2012 here: http:\/\/www.microsoft.com\/visualstudio\/en-us<\/a><\/p>\n\n\n\n

Spatial Data in the Entity Framework<\/h2>\n\n\n\n

Prior to Entity Framework 5.0 on .NET 4.5 consuming of the data above required using stored procedures or raw SQL commands to access the spatial data. In Entity Framework 5 however, Microsoft introduced the new DbGeometry<\/a> andDbGeography<\/a> types. These immutable location types provide a bunch of functionality for manipulating spatial points using geometry functions which in turn can be used to do common spatial queries like I described in the SQL syntax above.<\/p>\n\n\n\n

The DbGeography\/DbGeometry types are immutable, meaning that you can’t write to them once they’ve been created. They are a bit odd in that you need to use factory methods in order to instantiate them – they have no constructor() and you can’t assign to properties like Latitude and Longitude.<\/p>\n\n\n\n

It is important to mention that these types are defined in System.Data.Entity assembly in System.Data.Spatial<\/a> namespace. By now you have probably used types SqlGeometry<\/a> and SqlGeography<\/a> types, defined in Microsoft.SqlServer.Types<\/a> namespace<\/p>\n\n\n\n

Creating a Model with Spatial Data<\/h2>\n\n\n\n

Let’s start by creating a simple Entity Framework model that includes entities from sample databases Northwind<\/a> and SpatialDemo<\/a>. The entity named world contains a geom property of type DbGeometry<\/a>. Sample is using SQL Server 2012, but you could run it with SQL Server 2008.<\/p>\n\n\n\n

[EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=true)]\n[DataMemberAttribute()]\npublic global::System.Data.Spatial.DbGeometry geom\n{\n    get\n    {\n        return _geom;\n    }\n    set\n    {\n        OngeomChanging(value);\n        ReportPropertyChanging(\"geom\");\n        _geom = StructuralObject.SetValidValue(value, true, \"geom\");\n        ReportPropertyChanged(\"geom\");\n        OngeomChanged();\n    }\n }\nprivate global::System.Data.Spatial.DbGeometry _geom;\npartial void OngeomChanging(global::System.Data.Spatial.DbGeometry value);\npartial void OngeomChanged();<\/pre>\n\n\n\n
 Northwind Entities<\/p>\n\n\n\n
\"<\/a><\/figure>\n\n\n\n
Sample SpatialDemo database, including spatial data. Table world a filed from Geometry type, named \u201cgeom\u201d. This field  contains the contours of countries as polygons<\/p>\n\n\n\n
\"<\/a><\/figure>\n\n\n\n
Entity world, generated from SpatialDemo database contains a field \u201cgeom\u201d from Geometry type.<\/p>\n\n\n\n
\"<\/a><\/figure>\n\n\n\n
ASP.Net MVC 4 Application with Entity Framework 5 RC and Spatial data<\/strong><\/p>\n\n\n\n
Now it is  a pretty easy to use spatial data in ASP.Net MVC applications.<\/p>\n\n\n\n