Dynamic Select Sample (.NET)

This is a Data Abstract for .NET Samples topic

Purpose

The sample shows how to use the DynamicSelect feature to decrease network traffic and server load, retrieving only needed columns.

Examine the code

• Take a look at the bFill_OnClick event handler to see how you can fill the DataSet using the DynamicSelect feature:

this.fLocalDataSet = lUseDynamicSelect? (DataSet)new WorkersDataset(): (DataSet)new WorkersFullDataset();
this.workersBindingSource.DataSource = this.fLocalDataSet;
this.workersBindingSource.DataMember = "Workers";
this.dgvCustomers.DataSource = this.workersBindingSource;

this.remoteDataAdapter.DynamicSelect = lUseDynamicSelect;

...

this.remoteDataAdapter.Fill(this.fLocalDataSet);

• Look at the bUpdate_OnClick event handler to see how updates of the local DataSet can be applied to the SQL server database:

this.remoteDataAdapter.Update(this.fLocalDataSet);

Note that the Update operation always uses the DynamicSelect mode of the previous Fill operation.

Getting started

• Run the Sample Server.
• Run the Dynamic Select Sample.
• Try to fill and update the DataSet using the DynamicSelect feature.
• Look at the server log to see the SQL command used on the server and estimate the amount of data sent to the client application.
• Try to fill and update the DataSet not using the DynamicSelect feature.
• Look at the server log again to see the amount of data sent to the client application by the server.

Editions and Languages

• Data Abstract for .NET — available in C#, Embarcadero Prism and VB
• Data Abstract for Delphi — available here

Concepts Covered

• Dynamic Select

See Also

• Dynamic Where Sample
• DA SQL Sample
• PCTrade Sample Suite

Product: RemObjects Data Abstract
Available Editions: Data Abstract for .NET, Xcode, Delphi, Java and JavaScript

Glossary — Articles — Features — Library — Samples