ADO.Net Overview

Sunday, August 30, 2009

Background
• ADO (ActiveX Data Objects) was originally designed as a connected and tightly coupled model.
• ADO was more appropriate for the client/server architectures and not designed for a distributed and n-tier environment.
• ADO was not hierarchical like XML structures.
• ADO object was not well factored.

What is ADO.Net
• ADO .NET is a collection of classes, interfaces, structures, and enumerated types that manage data access from relational data stores within the .NET Framework
• ADO.NET collections are organized into the following namespace.
- System.Data,
- System.Data.OleDb,
- System.Data.SqlClient, etc.
• ADO .NET is an evolution from ADO.

Managed Providers
- Merges ADO and OLEDB into one layer
- Each provider contains a set of classes that implement common interfaces

Initial managed provider implementations:-
-ADO Managed Provider: provides access to any OLE DB data source
- SQL Server Managed Provider: provides optimal performance when using SQL Server
Data Access Style
ADO.NET access data into two ways.
- Connected mode: Forward-only, read-only mode
- Application issues query then reads back results and processes them.
- ADO.Net uses DataReader object in connected mode.
- Disconnected mode
- Application issues query then retrieves and stores results for processing of the data.
- Minimizes time connected to database
- ADO.Net uses DataSet object in disconnected mode.