Introduction

A filesystem is a method of storing data on a memory device like harddisk, pendrive..etc. This consists many disadvantages when large amount of data is to be stroed.

Problems with file storage

1. Data retrival will not be easier.
2. Data manipulations wil not be easier.
3. No security.
4. Data relatons can not be maintained,this leads data redundancy(data repitition). This consumes more memory and maintenance will not be easier.
The solution is database storage.

Database
Database is interrelated and integrated collection of data.

Types of database

1. Local databases(file based databases)
The data will be maintained in the form file.
Ex: Dbase,Foxpro,Foxbase...
2. Remote databases(server based data base)
The data will be managed by server.
Ex:Oracle,sql server...
3. Internet databases
OLTP -> Online Transaction processing.
OLAP -> Online Analytic process.
Index server.

Driver or Provider is a software component acts like a mediator between application and database.
Examples:
1. JET Driver(Joint Engine Technology)
It provides communication with local databases.
2. ODBC Driver(Open Database Connectivity)
It provides communication with remote database.
3. OLEDB Provider(Object Linking Embedding Database)
It provides communication with any type of data.

The application developer working with driver or provider will be complex. This is avoided by providing data access libraries.
1. DAO(Data Access Objects)
It is implementing JET driver programming to communicate with local databases.
2. RDO(Remote Data Objects)
It is implementing ODBC driver programming to communicate with remote databases.
3. ADO(Activex Database Objects)
It is implementing OLEDB, provides programming to communnicate with any type of data(universal data access)

Microsoft provided ADO library for web based application development. Later it is provided with all the Microsoft products.
-> In 1996 released IIS 3.0
It comes with ASP 1.0, this is provided with ADO 1.0 for connecting to any type of data on the web.
-> In 1998 released ADO 2.0/2.1
This version is provided with vb6.0, vc++ ....

Problems with ADO

1.  It is COM based library, COM is a binary standard to windows operating system.
2.  It requires performance improvement, this is possible by removing provider.
3.  It does not support purely disconnected implementaton.
4.  It does not support much integration with XML.

The solution in .Net is ADO.Net

Connected Architecture and Disconnected Architecture
When the memory component is maintaining database table information by maintaining connectivity with database, this is called Connected Architecture.
When the memory component is maintaining database table information without maintaining connectivity with database, this is called Disconnected Architecture.
Purely disconnected means memory component should never connect to database. This purely disconnected implementation provides lot of flexibility for data storage.

ADO.NET
It comes in the form of one library called system.data.dll, this provides two components.
1. .Net Data Provider: It supports connected architecture implementation
2. Dataset: It supports data storage with purely disconnected implementation & XML integration

.Net DataProvider :It is a collection of classes to implement connection oriented. .Net comes with 4(four types) of .Net data providers.

1. OLEDB .Net data provider.
2. Sqlserver .Net data provider.
3. Oracle .Net data provider.
4. ODBC .Net data provider.

Sqlserver.net and Oracle.net will implement nativ protocol programming of database, this makes communication faster.
.Net data provider can be daveloped by other companies, these are called third party .Net data providers.
Oracle corporation is providing Odb.net data provider. This is much compatible with Oracle 9i and later versions. This can be free download from Oracle corporation website.

Ado.Net connections and examples are provided in ADO.NET in C# - Part-II