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 rela-

tional data, XmlReaders expose efficient stream access to XML

(Con?, page 2)

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