13. Name the two properties of the GridView control that have to be specified to turn on sorting and paging.
The properties of the GridView control that need to be specified to turn on sorting and paging are as follows:
The AllowSorting property of the Gridview control indicates whether sorting is enabled or not. You should set the AllowSorting property to True to enable sorting.
The AllowPaging property of the Gridview control indicates whether paging is enabled or not. You should set the AllowPaging property to True to enable paging.
14. Mention different types of data providers available in .NET Framework.
.NET Framework Data Provider for SQL Server - Provides access to Microsoft SQL Server 7.0 or later version. It uses the System.Data.SqlClient namespace.
.NET Framework Data Provider for OLE DB - Provides access to databases exposed by using OLE DB. It uses the System.Data.OleDb namespace.
.NET Framework Data Provider for ODBC - Provides access to databases exposed by using ODBC. It uses the System.Data.Odbc namespace.
.NET Framework Data Provider for Oracle - Provides access to Oracle database 8.1.7 or later versions. It uses the System.Data.OracleClient namespace.
15. Which architecture does Datasets follow?
Datasets follow the disconnected data architecture.
16. What is the role of the DataSet object in ADO.NET?
One of the major component of ADO.NET is the DataSet object, which always remains disconnected from the database and reduces the load on the database.
17. What is a DataReader object?
The DataReader object helps in retrieving the data from a database in a forward-only, read-only mode. The base class for all the DataReader objects is the DbDataReader class.
The DataReader object is returned as a result of calling the ExecuteReader() method of the Command object. The DataReader object enables faster retrieval of data from databases and enhances the performance of .NET applications by providing rapid data access speed. However, it is less preferred as compared to the DataAdapter object because the DataReader object needs an Open connection till it completes reading all the rows of the specified table.
An Open connection to read data from large tables consumes most of the system resources. When multiple client applications simultaneously access a database by using the DataReader object, the performance of data retrieval and other related processes is substantially reduced. In such a case, the database might refuse connections to other .NET applications until other clients free the resources.
18. How can you identify whether or not any changes are made to the DataSet object since it was last loaded?
The DataSet object provides the following two methods to track down the changes:
The GetChanges() method - Returns the DataSet object, which is changed since it was loaded or since the AcceptChanges() method was executed.
The HasChanges() method - Indicates if any changes occurred since the DataSet object was loaded or after a call to the AcceptChanges() method was made.
If you want to revert all changes since the DataSet object was loaded, use the RejectChanges() method.