Introduction To ADO.NET

In this article I explain the basic details of ADO.NET.


ADO stands for Active Data Object and ADO.NET is a set of .NET libraries for ADO.

What ADO.NET is
ADO.NET is a collection of managed libraries used by .Net applications for data source communication using a driver or provider.

ADO.NET provides libraries for the datasource communication under the following namespaces.

  1. system.Data
  2. system.Data.OleDb
  3. system.Data.SqlClient
  4. system.Data.OracleClient
  5. system.Data.Odbc

Let's see the details of all these namespaces.

1. System.Data

This namespace is used for holding and managing data on a client machine.

This namespace contains the following set of classes:

  1. DataSet
  2. DataTable
  3. DataRow
  4. DataView
  5. DataColoum
  6. DataRelation

2. System.Data.OleDb

This namespace can communicate with any Data Sourcem like files, databases, indexing servers and so on using the “OleDb” Provider.

3. System.Data.SqlClient

This namespace can communicate with “SQL Server” DataBase only using SqlClient Providers.

4. System.Data.OracleClient

This namespace can communicate with an “Oracle” DataBase only using OracleClient Providers.

5. System.Data.ODBC

This namespace contains the same set of classes as the following:

  1. Connection
  2. command
  3. DataReader
  4. DataAdaptar
  5. CommandBuilder
  6. Parameter


Here each class is reffered to by prefexing with their namespace before the class name to discriminate between each other as in the following:

OleDbConnection: OledbCommand
SqlConnection: SqlCommand
OracleConnection: OracleCommand

Performance Operations on a DataSource

Each and every operation we perform on a data source involves the following 3 steps:

  1. Establishing a connection with a DataSource.
  2. Sending a request as an SQL Statement.
  3. Capturing results by the data Source.

1. Establishing a Connection
Connecting is a collection of attribures that are used for connecting with the data source. Those are:

  1. Provider
  2. Data Source
  3. User Id and Password
  4. Database or Initial Catlog
  5. Trusted Connection or Intregrated Security
  6. DSN

1. Provider

As explained earlier, a provider is required for connectiong with any data source where we use a different provider for each data source.

For example:

Oracle: MsdOra
SqlClient: SqlOledb.
Microsoft Access or Excel: Microsoft jet OleDb 4.0
Microsoft Indexing Server: Msidx.

2. DataSource

It is the name of the target machine to which we want to correct with. This is optional when the data is on the local machine.

3. User id and password

Since databases are secured places for storing data, to connect with them we require a valid user name and password.

Oracle: scott/tiger
SQL Server: sa/<pwd>.

For SQL Server the default user name is “sa” and the password is that which we provide at the time of installation of SQL Server.

4. DataBase Or Initial Catlog

These attributes are used when connecting with SQL Server to specify the name of the database that we want to connect with.

5. Trusted-connection or Intergrated Security

These attributes are also used when connectiong with SQL Server only to specify that we want to use Windows Authentication.

6. DSN
This attribute is used when connecting with data sources using ODBC Drivers.

For example:

“provider =sqldb;userid=sa;password =<pwd>;DataBase=<DBname>;[DataSource=<Server>]”

Members of the Connection Class

1. Open( )

Open a connection with data source.

2. Close( )

Close the connection that is open.

3. State

Get the status of the connection.

4. ConnectionString

Gets or sets a connection string associated with the connection object.

I hope you understand the basic concepts related to ADO.NET.

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