Download It is possible to use a simple SQL and access the

Access Web Services as Database:
Abhishek Khanolkar
Introduction:
It is possible to use a simple SQL and access the database from the web Application. But, is it possible to
connect the disparate environments like the web services and the web applications? In other words is it
possible to consume data propagated by the web services based in the database?
The W3C defines a Web service as a software system designed to support interoperable machine-tomachine interaction over a network [2]. There are many technologies involved in the operation of Web
Services. First, the WSDL which is the web services definition language. It is a format describing how to
communicate using web services. Second, the XML (Extensive markup Language). XML is a special
purpose markup language used to describe different data types. Thirdly, SOAP is a protocol used for
exchanging XML messages over the internet using HTTP. A combination of WSDL, SOAP and XML is
used to provide web services over the internet.
In disparate environments web services make crossing the environment barriers easier because web
services communicate using XML and XML is platform independent language. If you use Web Sphere
Information Integrator it is possible to access data propagated by the web service. It is as easier as
accessing database from the web applications.
Research:
In this paper I am using DB2 as a database, IBM’s Rational Application Developer as an Application
development package and Web Sphere Information Integrator as a middleware. All the three are IBM’s
products and they are available free as a trial version. In the paper I used a tutorial available on IBM’s
website. Following the instructions in the tutorials I had to download 1. DB2 database, 2. Rational
Application Developer trial version and 3. WebSphere Information Integrator. Each of this software’s has
size ranging from 500 Mb to 4 Gb or more.
DB2:
DB2 is IBM’s Relational Database management System. IBM now calls it data server. DB2 Universal
Database is a free version of database made available by IBM. Oracle and Microsoft has also made
available their database as free versions. The good thing about DB2 is that it lets users download only
those features essential to the user, thus avoiding huge and hefty downloads.
“Information integration can be loosely defined as unifying data within an enterprise and surfacing it to end
users and applications as trusted information”[3]. WebSphere Information Integrator acts as a middleware
and provides all the necessary means to unifying data and providing it to the end user. In this case the data
is the web service.
IBM WebSphere Information Integration capabilities:
“Information integration is the process of integrating and transforming data and content to deliver
authoritative, consistent, timely and complete information, and governing its quality throughout its life
cycle”[4]. The main capabilities of WebSphere information Integrator are 1. Cleanse information, 2.
Connect information 3. Federate information, 4. Transform Information and finally 5. Understand
information. Information Integration saves lot of money for example ‘The State of New Jersey
Saved an estimated $500,000 in IT development costs and expects to save as much as $8 million dollars
overall by automating the information integration of data from four disparate systems into agency specific
data marts ’[4].
IBM’s RAD is originally WSAD (WebSphere Application Developer). RAD is and Integrated
Development Environment (IDE) for designing, constructing Web services, and Java 2 Enterprise Edition
(J2EE) applications. J2EE includes technologies such as Servlets and JSP.
In any organization data can be generated from various sources. The data needs to be consumed and IBM’s
answer to that is Service Oriented Architecture (SOA). SOA makes use of the existing data and processes
and creates a new flexible model.
Checking Web Service:
The first step in the process (Tutorials) is to check if the web service is working. www.xmethods.com is a
web site which lists many web services. Once you are on the site you click full services link and that gives
the list of all the available web services. Then click URL of the web service and that open up the WSDL
code behind the web service. This code is opened in a web browser, copy the URL. The URL is used in the
DB2 database.
Starting DB2:
The main job of DB2 is to store the web service and call it using SQL. To start a new sample database is
created and given an alias and its schema is defined. Inside the database create a wrapper object; in the
wrapper object you define the data source as the web service. Then you define the server definition and
inside the server definition paste the URL copied from www.xmethods.com . Once that is done you need to
test the connection and run the SQL statement with relevant condition. The result is a table which shows
the result. In my testing I used the web service which the date of Good Friday holiday when the year is
provided. It worked fine.
Develop an Application:
Application development is done using WSAD or RAD. The database at the back is DB2 which had the
web service and has been tested to work. First create a work space to work on, and then insert a text-field
on the JSP editable region. Add a button on the JSP page and link the text field to the web service. Connect
the button to action JSP which calls a web service function. Save and run the application on server, the
output will be displayed on the JSP page. Make sure you use the web sphere V6 server. The tutorial
explains this step by step process to do the job.
Future Work:
In future it is expected that more and more application are going to be combined in to one single unit. This
study could form a good example of that, sometime ago it was hard to imagine that database, web services
and applications could be combined to create one singe application.
Related Work:
Oracle has Web Service Manager to mange Web Service and defines the policies of Web Services [5]. This
product does not allow accessing web service as database. Microsoft’s SQL server does not have the same
kind of features as RAD and DB2. It can be assumed that IBM is the only product which offers such
possibilities. This gives DB2 an edge over others in this field. It is very essential for companies to handle
their web services effectively and bringing them under the database and closer to application is good. I
would like to take closer look to ascertain if there are other products offering such services.
Conclusion:
Accessing web services from database is an excellent tool. Using a middleware like the WebSphere
Information Integrator it was possible to combine the power of Relational Database like DB2 and Web
Service. WSAD makes the job easier by its ready to use tools and the combination of the three is awesome.
In the study I got to use RAD, WSII and DB2, it was enriching experience. IBM products like RAD are
giving a tough competition to the .NET framework. There was no coding in the entire application
development. All that needed to be done was select settings for the application.
References:
1) https://www6.software.ibm.com/dw/education/wes/wesaccesswsdb/index.html Retrieved on
9/29/2006.
2) http://en.wikipedia.org/wiki/SOAP retrieved on 9/29/2006.
3) http://www-306.ibm.com/software/sw-library/en_US/detail/I228969X13039L28.html Retrieved
on 9/22/06
4) http://www-306.ibm.com/software/data/integration/en_US/capabilities/ Retrieved on 9/22/06
5) http://www.oracle.com/technology/products/webservices_manager/index.html