You can use the workbench to create Web services that expose
database operations (SQL SELECT and DML statements, XQuery expressions,
or calls to stored procedures) to client applications.
About this task
Web services accept XML messages or URL-encoded parameter
strings as requests for database operations. (In the rest of this
documentation, XML messages and URL-encoded parameter strings are
both referred to as "messages," except where a distinction between
the two is necessary.) Web services return results and result sets
in XML messages. For operations that perform SQL inserts, updates,
and deletes, Web services return a count of the number of new, changed,
or deleted rows.
A Web service performs the following actions
when it receives a message that contains a request:
- Looks in the message to determine the requested database
operation.
- Extracts the input parameters from the message.
- Prepares and executes the statement.
- Retrieves the result of the operation.
- Generates the output XML message that contains the result.
- Sends the output message to the requesting client application.
You have the option of configuring XSL transformations on input
and output messages.
XML messages that request an operation
and XML messages that return the results of an operation are tagged
according to a default XML schema that the workbench generates for
each operation. This default schema performs the following functions:
- Maps input and output parameters to XML tags
- Maps columns to XML tags
- Maps SQL data types to XML data types
- Maps Web service operations to XML tags
- Provides the general structure of input and output messages
After you develop a Web service, with one click you can
deploy it to a Web server. The workbench deploys Web services as Java™ Platform, Enterprise Edition (Java EE) Web Archive (WAR) files. You can also
use the workbench to generate deployable files only or artifacts for DataPower® and then deploy them yourself.