Web services and DB2

Web services are sets of business functions that applications or other Web services can invoke over the Internet. A Web service performs a useful service on behalf of a requester. That service can span many businesses and industries.

Example: Assume that an airline reservation system is a Web service. By offering this service, the airline makes it easier for its customers to integrate the service into their travel-planning applications. And a supplier can use the service to make its inventory and pricing information accessible to its buyers.

Web services let you access data from a variety of databases and Internet locations. DB2 can act as a Web services requester, enabling DB2 applications to invoke Web Services through SQL. DB2 can also act as a Web Services provider through DB2 WORF (Web services object runtime framework), in conjunction with WebSphere Application Server, enabling you to access DB2 data and stored procedures as Web Services.

The functions that Web services perform can be anything from simple requests to complicated business processes. You can define a basic Web service by using standard SQL statements and DB2 XML Extender stored procedures.

Using XML for data exchange, Web services support the interaction between a service provider and a service requester that is independent of platforms and programming languages. The Web services infrastructure includes these basic elements:

• Simple Object Access Protocol (SOAP) uses XML messages for exchanging information between service providers and service requesters. SOAP defines components of Web services, which include XML messages, data types that applications use, and remote procedure calls and responses.

• Web Services Description Language (WSDL) describes what a Web service can do, where the service resides, and how to invoke the service. WSDL specifies an XML vocabulary that contains all information that is needed for integration and that automates communication between Web services applications.

• Universal Description, Discovery, and Integration (UDDI) provides a registry of business information, analogous to a telephone directory, that users and applications use to find required Web services.

You can use WebSphere products to build Web service applications. WebSphere Studio provides tools for creating Web services that include WSDL interfaces and publishing directly to a UDDI registry.