This is in continuation of my earlier two posts - AutoCAD Map 3D API Training content: Part-1 & Part 2 . In this post I am going to introduce you to FDO API.
Feature Data Object (in short FDO) is essentially a Data Access Technology which is based on a set of APIs used for storing, managing, and updating GIS / Geospatial data regardless of where it is stored. FDO uses a provider-based model for supporting a variety of geospatial data sources, where each provider typically supports a particular data format or data store. FDO is open source software licensed under the LGPL.
FDO provides a model for extending API interface to additional data source technologies. The generic API is extensible and it is possible to add custom commands to a particular provider. A FDO provider is a specific implementation of the FDO API that provides access to date stored in a particular data source technology. For example, the MySQL provider provides access to GIS data stored in a MySQL database and the OSGeo FDO Provider for SHP provides access to GIS data stored in a SHP file. The extent to which a provider implements the FDO API is limited by the native capabilities of the underlying data source technology.
A client application creates a connection to a provider and then uses the connection object to create command objects for FDO actions such as Select. The client uses the command object to set the command parameters with the option of leaving some parameters with default values. Where appropriate such as in the case of Select, execution of the command returns a reader object containing the results of the command.
A client application can use the FDO Capabilities API to determine what services a particular provider offers. For example, the OSGeo FDO Provider for SDF supports the insertion of data, and the OSGeo FDO Provider for WMS does not.
Comprehensive documentation on FDO Data Access Technology is available at FDO OSGeo site as well as Autodesk WikiHelp page. There is a “Getting Started” chapter in “The Essential FDO” wikihelp page which will help you to jump start using FDO API. “Development Practices” and “FDO Cookbook” are other two valuable chapters I would recommend to go through if you plan to create a custom FDO provider.
This Chapter 3 will help you to understand working with 'FDO API' and application development using Geospatial Platform API for AutoCAD Map 3D and AIMS.
I hope this is useful to you!
