SharePoint et MOSS au Quotidien avec EROL
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SharePoint et MOSS au Quotidien avec EROL
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What is the Business Data Catalog (BDC) and the LOB ?
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. |
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