ADO.NET Cookbook

4.11. Updating Server Data Using a Web Service

Problem

You want to update a data source using an XML web service and use the web service from your client application.

Solution

Use a DataSet object.

The XML web service code contains two methods:

LoadOrders( )

Creates and returns a DataSet containing the Orders and Order Details tables from Northwind and a DataRelation between those tables.

UpdateOrders( )

Takes a DataSet argument containing the changes made to the DataSet created by the LoadOrders( ) method, creates two DataAdapter objects with CommandBuilder generated update logic for each, and uses the DataAdapter objects to update the Orders and Order Details tables in Northwind.

The client-side code contains two event handlers:

Form.Load

Sets up the example by calling the LoadOrders( ) method in the web service to populate a DataSet. The default view of the Orders table is bound to the data grid on the form.

Update Button.Click

Calls the UpdateOrders( ) method in the web service passing a DataSet containing changes made to the DataSet since the form was loaded or since the last time the UpdateOrders( ) method was called.

The C# code for the XML web service is shown in Example 4-25.

Example 4-25. File: NorthwindServiceCS.asmx.cs

// Namespaces, variables, and constants using System; using System.ComponentModel; using System.Web.Services; using System.Configuration; using System.Data; using System.Data.SqlClient; public const String ORDERS_TABLE = "Orders"; public const String ORDERDETAILS_TABLE ...