In this blog post, we will explore the new spatial data type support in SQL Server 2008. Spatial data refers to data that has a spatial aspect, such as coordinates or shapes. We will discuss the need for spatial support in applications and the two core spatial data types in SQL Server: Geometry and Geography.

Why Spatial Data?

In today’s world, spatial data is becoming increasingly important in various applications. From mapping and navigation to analyzing customer locations and predicting bus arrival times, spatial data plays a crucial role. With the rise of GPS devices and geo-tagged data, it is essential for developers to understand how to work with spatial data in their applications.

The Geometry and Geography Data Types

In SQL Server 2008, there are two main spatial data types: Geometry and Geography. The Geometry data type is based on the Cartesian coordinate system and is suitable for representing simple coordinates in a two or three-dimensional space. On the other hand, the Geography data type uses latitude and longitude coordinates to represent points, lines, polygons, and collections of these. It is more suitable for working with GIS data that is based on a round earth model.

Working with Spatial Data in SQL Server

Both the Geometry and Geography data types are implemented as user-defined types (UDTs) in the SQL Server database engine. These UDTs are implemented as .NET Common Language Runtime (CLR) types. Understanding some basic object-oriented principles is helpful when working with these spatial data types.

A class in object-oriented programming can be seen as a blueprint for a particular type. It encapsulates its implementation details behind properties and methods. Inheritance and composition are two important concepts in object-oriented programming that allow classes to be related to one another.

In the case of spatial data types, the Geometry and Geography classes are defined as abstract classes in the database engine. They provide a foundation for more specialized classes that inherit their functionality. These specialized classes can be instantiated and used to work with specific spatial data.

Conclusion

In this blog post, we have introduced the concept of spatial data and discussed the Geometry and Geography data types in SQL Server. Understanding spatial data and how to work with it is essential for developers working on applications that involve mapping, location-based services, and analysis of spatial information.

In the next blog post, we will dive deeper into the class diagrams for the Geometry and Geography classes and explore some TSQL code examples to demonstrate their usage.