.NET Questions

The following are the usages of the Command object in AD0.NET:

The Command object in AD0.NET executes a command against the database and retrieves a DataReader or DataSet object.

  =>  It also executes the INSERT, UPDATE, or DELETE command against the database.
  =>  All the command objects are derived from the DbCommand class.
  =>  The command object is represented by two classes: SqlCommand and OleDbCommand.
  =>  The Command object provides three methods to execute commands on the database:
  =>  The ExecuteNonQuery() method executes the commands and does not return any value.
  =>  The ExecuteScalar() method returns a single value from a database query.
  =>  The ExecuteReader() method returns a result set by using the DataReader object.

The session time-out value is specified in the web.config file within sessionstate element.You can change the session time-out setting by changing value of timeout attribute of sessionstate element in web.config file.

Value type :

• Stores the data


• The value of value types is stored on the managed stack


• They are lighter objects 


• One variable can have only one value

Reference Type :

• Stores the reference to the data


• A reference type is allocated on the heap


• They are heavier objects


• Several variables can reference the same data

You can prevent a class from overriding in C# by using the sealed keyword; whereas, the NotInheritable keyword is used to prevent a class from overriding in Visual Basic.

.NET does not support multiple inheritance directly because in .NET, a class cannot inherit from more than one class. .NET supports multiple inheritance through interfaces.

The ServiceInstaller class, also known as the project installer class, is used to install a Windows service.

You should not use AJAX if:

             =>  You want the page to show in a search engine, such as Google, because WebCrawler does not execute JavaScript code.

             =>  The browser does not support JavaScript.

             =>  You want to create a secure application.

The following are the usages of the Command object in AD0.NET:

The Command object in AD0.NET executes a command against the database and retrieves a DataReader or DataSet object.

  =>  It also executes the INSERT, UPDATE, or DELETE command against the database.
  =>  All the command objects are derived from the DbCommand class.
  =>  The command object is represented by two classes: SqlCommand and OleDbCommand.
  =>  The Command object provides three methods to execute commands on the database:
  =>  The ExecuteNonQuery() method executes the commands and does not return any value.
  =>  The ExecuteScalar() method returns a single value from a database query.
  =>  The ExecuteReader() method returns a result set by using the DataReader object.