Using a Web service to update the database (Obsolete) – PB Docs 2019

You can use a DataWindow with a Web service data source to update
a database. Support for updating data requires one or more WSDL files
that describe methods and parameters that can be called by the
DataWindow engine for insert, delete, or update operations.

Generating or selecting an
assembly

The WSDL files are not required on runtime computers. They are
used to generate assembly files that are deployed with the application.
If you have an existing assembly file that allows you to update data in
your DataWindow objects, you can select that assembly instead of
generating a new one from the Web Services Update dialog box. You can
generate or select separate assemblies for insert, delete, and update
operations.

Insert, delete, and update
operations

The insert, delete, and update operations imply different things
depending on the original data source. When you insert a DataWindow row
for an RDBMS, a new row is added to the database; when the data source
is an array of structures, a new structure instance is added to the
array; and when the data source is an array of simple types, a new
instance of the simple type is added to the array. The delete operation
removes a database row or an instance in an array, and the update
operation modifies a database row or an instance in an array.

For each operation, you must map DataWindow column values or
expressions to Web service input parameters. At runtime when performing
one of these operations, the DataWindow binds column or expression
values to parameters as instructed and calls the Web service method. The
DataWindow engine does not know what actually happens in the Web service
component (that is, how the component implements the update), only
whether it returns a success or failure message.

The following figure displays the Web Service Update dialog box.
You use this dialog box to bind to Web service parameters to DataWindow
columns or expressions. Unlike the retrieve call, DataWindow update
operations can handle bidirectional parameters. However, you can select
an expression or computed column only for an update method input
parameter.

If the parameter is to receive a column value, indicate whether
the parameter will receive the updated column value entered through the
DataWindow object or retain the original column value from the
database.

Typically, you select Use Original when the Web service parameter
is used in the WHERE clause of an UPDATE or DELETE SQL statement for a
Web service method. If you do not select Use Original, the parameter
uses the new value entered for that column. Typically, you would use the
new value when the Web service parameter is needed for an INSERT SQL
statement for the method, or if it is set in an UPDATE SQL
statement.

Regenerating an
assembly

If you need to regenerate an assembly for a DataWindow that uses a
Web service data source for retrieval, update, insert, or delete
operations, you must add the following line to the [DataWindow] section
of the PB.INI file:

After you set this property in the PB.INI file, PowerBuilder
regenerates the assembly on each compilation of the target containing
the DataWindow.

Using the WSError event

Because a DataWindow with a Web service data source does not pass
back failure messages in a return code during retrieve, insert, or
update operations, you must use the WSError event to obtain such error
information.

For more information on the WSError event, see the section called “WSError (Obsolete)” in DataWindow Reference.

The WebServiceException
object

Because a DataWindow with a Web service data source does not pass
back failure messages in a return code during retrieve, insert, or
update operations, you must use the WebServiceException object to obtain
such error information. The parameters in the following table are
exposed in the WebServiceException object when an error occurs: