Database Reference
In-Depth Information
C H A P T E R 7
OData with SQL Azure
Technical authors typically write topics because they're excited about the technology about which
they're writing and want to share their excitement with the readers. As the authors work through the
chapters, they get to illustrate the exciting ways in which to use the technology and apply it in real-world
scenarios. Occasionally, they get to work on a chapter where the technology is so cool that they don't
look forward to the chapter ending.
This is one of those chapters. It's about OData, a platform-independent protocol for querying and
updating data. Using OData, you can get at your data even from a mobile phone.
How cool is it to hook up a Windows Mobile 7 phone using OData to a SQL Azure database to view
your data, with almost the greatest of ease? Very cool. By the time you get to the end of this chapter, we
hope you agree.
You may be wondering what OData is, and how it and Windows Mobile relates to SQL Azure. This
chapter answers those questions, among others, by discussing the OData protocol, what it is and why it
exists, and how it relates to SQL Azure. You also learn how to use OData to query your SQL Azure
database and then build applications (such as a Windows Mobile phone application) in which to display
data from your Azure database via OData.
Services are a critical and fundamental part of application development today, and even more so in
the applications of tomorrow. This is why technologies such as WCF Data Services and OData are
covered in this topic, with OData covered specifically in this chapter as it relates to SQL Azure. OData
continues to be a widely accepted protocol used in many applications and environments that use web
technologies such as HTTP. Let's dive in to OData.
OData Overview
OData stands for Open Data protocol. It's a REST-based web protocol for querying and updating data
completely independent of the platform or source. OData accomplishes this by utilizing and enhancing
existing web technologies such as HTTP, JavaScript Object Notation (JSON), and the Atom Publishing
Protocol (AtomPub). Through OData, you can gain access to a multitude of different applications and
services from a variety of sources including relational databases, file systems, and even content-
management systems.
The OData protocol came about from experiences implementing AtomPub clients and servers in an
assortment of products over the past few years. OData relies on URIs for resource identification, which
provides consistent interoperation with the Web, committing to an HTTP-based and uniform interface
for interacting with the different sources. OData is committed to the fundamental web principles; this
gives OData its great ability to integrate and interoperate with a plethora of services, clients, tools, and
servers.
