ADO.NET in a Nutshell

Automatic Transactions

Microsoft Transaction Server (MTS), COM+ 1.0, and the .NET CLR support the same automatic distributed transaction model. The .NET Framework provides support for transactional components through COM+ services. There are two key benefits to COM+ transactions:

• They allow distributed transactions that span multiple data sources.

• Objects that can participate in COM+ transactions are free from having to anticipate how they might be used within a transaction. A client can perform different tasks with multiple objects, all in the context of a single transaction without the participating objects being aware of the transaction.

Instances of a .NET Framework class can participate in automatic transactions. Once an object is marked to participate in a transaction, it automatically executes within a transaction. This transactional behavior is controlled by the value of the transaction attribute for the .NET class, ASP.NET page, or XML web service method using the object. This allows the instantiated object to be configured programmatically to participate automatically in an existing transaction, to start a new transaction, or to not participate in a transaction.

When a transactional object accesses a data resource, a transaction occurs according to the value of the declarative transaction attribute of the object. When the transactional object accesses a data resource, the data driver enlists in the transaction through the distributed transaction coordinator (DTC).

During ...