(.NET - ADO.NET) Asynchronous Command Execution in ADO.NET 2.0

Get an overview of the new asynchronous execution functionality in ADO.NET 2.0, the scenarios it was developed to enable, plus some of the issues to keep in mind when using this feature.

In the 2.0 release of ADO.NET, we not only wanted to make existing scenarios easier, but also enable new scenarios that either were just not possible before, or were far from ideal.

Asynchronous command execution is a good example of that. In releases of ADO.NET before 2.0, it wasn't possible to execute a command and not wait for it to complete before continuing execution. The addition of an asynchronous API enables scenarios where it is important for the application to continue execution without waiting for the database to complete the operation.

In this article, I'll cover the basics of the asynchronous database API and a couple of scenarios where this API is useful. Although we designed the API to work with any data access provider, SqlClient—the .NET data access provider for SQL Server—is the only one of the four providers included with .NET that actually supports it. Because of that, I'll use SqlClient throughout the rest of the article in the samples and descriptions of methods and classes. Bear in mind that third-party provider writers can implement this asynchronous API as well, so we may see more databases that can be accessed asynchronously. Simply change the class and method names accordingly to use these samples with other databases.