What is the Business Data Catalog (BDC)?

The Business Data Catalog (BDC) is a new innovative framework created by the Office team to provide MOSS sites with integration into line-of-business (LOB) systems such as those created by SAP, Seibel, and PeopleSoft. The BDC additionally provides the means to integrate data directly from database systems such as SQL Server and Oracle. The BDC is included with the Enterprise Edition of MOSS.


While SharePoint Portal Server 2003 (SPS) has made it possible to integrate portal sites with LOB systems, it has required you to write custom code to manage connections and retrieve the data you need to display. Furthermore, the code required changes significantly as you switch between back-end systems from vendors such as SAP and PeopleSoft. The BDC, on the other hand, has been designed to enable you to integrate data from LOB systems without requiring you to write custom code for managing connections and retrieving data.
The design of the BDC is based on metadata that describes the location and format of data within LOB systems in terms of entities and methods. The BDC also provides a standardized method execution engine capable of reading this metadata and retrieving read-only data from LOB systems which is then returned to MOSS in a standard format.
The connectivity between the BDC and traditional LOB systems is achieved using standard Web services. The metadata required defines BDC methods for executing Web service operations. The connectivity between the BDC and database systems is achieved using ADO.NET providers. In this case, the metadata required defines BDC methods for executing SQL statements and/or stored procedures.


The first step in using the BDC is to author an XML file containing the metadata to connect to a back-end system. When you author metadata for the BDC, you define the data you want to retrieve in terms of entities. For example, you might define a customer as one entity and an invoice as another entity. The BDC metadata format also lets you define associations between entities in scenarios when there is a one-to-many relationship such as one that might exist between customers and invoices.


The definition of a BDC entity contains identifiers, properties, and methods. The methods define how the BDC interacts with entry points exposed by the back-end system. For a back-end system accessible through Web services, methods define the names of the Web service operations and the parameters required to call them. For a back-end system that is a database such as SQL Server or Oracle, methods define the names of stored procedure and SQL statements.


Entities can also define actions. A BDC action is used to dynamically parse together the URL behind a hyperlink that allows a user to navigate from a page in an Office SharePoint Server 2007 portal site to another location. For example, an action defined on a BDC customer entity could be written to redirect users to a Web page in an SAP application that supports updates to customer information. Actions were designed to support scenarios where the BDC is used to display read-only data and to bootstrap the user into another application when updating or some other type of external operation is required.


Once you have authored or acquired the XML file with the required BDC metadata for a back-end system, you must import it into the BDC within the scope of a particular SSP to create what is known as a BDC application. You can accomplish this importing process using the SSP administrative Web pages. You can alternatively import an XML file with BDC metadata using custom code written against the BDC administrative object model.


Once you have imported the required metadata to create a BDC application, there are several out-of-the-box techniques to leverage and display its data within a portal site. Office SharePoint Server 2007 ships with a set of Business Web Parts that can be quickly added to pages to query and display BDC data. You can also add new columns to lists and document libraries based on an entity defined in a BDC application. A user editing a column based on a BDC entity is automatically presented with a user interface making it possible to query the back-end system.


The BDC has been designed to integrate with the Office SharePoint Server 2007 Search Service. For example, a back-end system and its entities can be defined as a content source so that the Office SharePoint Server 2007 indexing service will crawl through its data and build indexes for the Office SharePoint Server 2007 search engine. This becomes a powerful feature because it allows users to discover data from back-end systems about things like customers and invoices when running standard search queries through both Office SharePoint Server 2007 portal sites and standard Windows SharePoint Services 3.0 sites.


The BDC provides convenient features to map data from a BDC entity to properties in a user profile and to synchronize this data at periodic intervals. For example, if your company has an SAP system that contains employee data you like to include in user profiles, such as phone numbers or social security numbers, you can configure this type of data importing without writing any custom code.


Finally, BDC entities can also be accessed programmatically using custom code written against the BDC object model. This makes it possible to write custom Web Parts as well as other server-side components and services that run their own BDC queries. One nice aspect of writing code to query BDC entities is that you don’t have to worry about managing connections or whether you are accessing the back-end system through Web services or ADO.NET. All those details are abstracted away by BDC metadata and the BDC execution engine.