The LA Fox Developer Newsletter

November 2000

“.NET” (Con? from page 6)

Figure 4 ADO+ Architecture

Just like its native counterpart, ADO+ defines classes for connecting to, issuing commands against, and retrieving results from data stores. These classes are implemented by managed data providers. The ADO+ Connection and Command objects look nearly identical to those in ADO, and a new class called a DataReader provides the ability to retrieve results through a high-performance stream API. The DataReader is functionally equivalent to a forward-only, read-only ADO Recordset, but DataReaders are designed to minimize the number of in-

memory objects created to avoid garbage collection and improve performance. The .NET Framework includes managed data providers for Microsoft SQL ServerTM and any data store that can be access via OLE DB.

One of the major innovations of ADO+ is the introduction of the Dataset. A Dataset is an in-memory data cache providing a relational view of the data. Datasets know nothing about the source of their data-the Dataset may be created and populated programmatically or by loading data from a data store. No matter where the data comes from, it is manipulated using the same programming model and uses the same underlying cache. Developers using the .NET platform will be able to use the Dataset in place of the disconnected recordset in classic

ADO.

Managed data providers expose a DataSetCommand object for interfacing between data stores and Datasets. The DataSetCommand uses ADO+ Connections and Commands to fill Datasets from data stores, and resolve changes from the Dataset back to data stores.

Just as DataReaders expose efficient stream access to relational data, XmlReaders expose efficient stream access to XML

(Con?, page 2)

Page 7