Open Data Protocol (OData) is quickly gaining popularity as a web protocol for querying and updating data. A few Microsoft products already expose their functionality as OData services, including SharePoint 2010, SQL Azure and SQL Server 2008 R2 Reporting Services. OData is a set of extensions of the ATOM protocol to makes it easier to share data over the web.
In SharePoint Server 2010 every SharePoint list is exposed through an OData REST API (you might also see some people referring to it as WCF Data Services) – which you can access using the following URL format:
- http://[sharepointserver]/_vti_bin/listdata.svc – returns an ATOM document describing the different lists which are available in that specific site.
- http://[sharepointserver]/_vti_bin/listdata.svc/Projects – returns an entry for every single list item in the “Projects” list
- http://[sharepointserver]/_vti_bin/listdata.svc/Projects(2) – returns a specific list item with ID=2 from the projects list