Getting Started with IBM Data Studio for DB2

282 Getting Started with IBM Data Studio for DB2
10.1 Data web services: The big picture
Web services, in general, are standards that allow applications to share information
through services on the web. There are a multitude of materials on the web about web
services, and you can also refer to the ebook entitled Getting Started with Web 2.0 for
more information. In summary, however, web services are designed to allow for
communication between machines in a loosely coupled fashion. This can be accomplished
by use of a Web Services Description Language (WSDL) XML document that provides the
description required by the invoker to call the service (where is the service, what binding to
use, etc) and to understand the messages (in XML) returned by the service.
Data web services, in particular, refer to the ability to wrap web services around the logic
provide by the database. For example, you might already have a SQL script or stored
procedure that provides business logic for returning the current price of a particular item in
inventory from the database. Using data web services, you are simply making it much
easier for a web application (or other client) to start that capability, perhaps even as simple
as putting the HTTP request in a web browser.
This approach to creating a web service based on existing database operations/business
logic is called “bottom up” as opposed to a to ”top down” approach in which the web
services description is defined first and then logic is provided to map to that particular
description.
Data Studio (and Optim Development Studio) supports the development and deployment of
data web services without you having to write a single line of code. Figure 10.1 provides an
overview of data web services using Data Studio.
Figure 10.1 - Developing data web services with Data Studio