What is the meaning of this line in ASP.NET :
<%@ import Namespace="System.Data.OracleClient" %>
<%@ import Namespace="System.Data.SqlClient" %>
<%@ import Namespace="System.Data.Oledb" %>
<%@ import Namespace="System.Data.Odbc" %>
If you are using any one of the above lines in your code ,that means you are using ADO.NET to access data. And inside the code you will be using the corresponding DATAPROVIDER listed here.
Data Provider for Oracle (System.Data.OracleClient).
Data Provider for SQL Server (System.Data.SqlClient).
(ADO stands for Microsoft Activex Data Object)
Actually this DataProvider is again divided into a number of objects like this:
Connection object ( OracleConnection,SqlConnection, OleDbConnection, OdbcConnection)
Apart from the above, the ADO.NET consisits of another item known as DATATSET.
Carefully watch the Diagram given at the top. To get data from the database, you have to follow the Red Path or the Blue Path. In the Red Path, DataReader is there. It is very fast. But it is forward-only which means it is useful for JUST display the records (not good for updating).
The Blue path has DataSet which has lot many features.