ADO.NET Cookbook

4.7. Updating a Data Source with Data from a Different Data Source

Problem

You want to update a data source using changes made to another data source for data replication or auditing purposes.

Solution

Use the GetChanges( ) method of the DataSet to identify changes made to a DataSet and replicate these changes into a different data source.

The sample code contains two event handlers:

Form.Load

Sets up the example by setting up two DataSet objects each containing a single table. The first table is filled with the Customers table from Northwind stored in SQL Server; the second is filled with the Customers table from Northwind stored in a MSDE instance. The default view of each table is bound to a data grid on the form.

Update Destination Button.Click

Creates a new DataSet containing only the records that have changed in the original data source. This DataSet is then used to apply the changes to a second data source using its DataAdapter; the DataSet for the second data source is reloaded. Finally, the first data source is updated with the changes.

The C# code is shown in Example 4-10.

Example 4-10. File: UpdateDataFromDifferentDataSourceForm.cs

// Namespaces, variables, and constants using System; using System.Configuration; using System.Windows.Forms; using System.Data; using System.Data.SqlClient; private DataSet dsSource, dsDest; private SqlDataAdapter daSource, daDest; // . . . private void UpdateDataFromDifferentDataSourceForm_Load(object sender, System.EventArgs e) { // Create the DataAdapter ...