What is the use of command objects and what are the methods provided by the command object ?

They are used to connect connection object to Datareader or dataset.Following are the methods provided by command object. ExecuteNonQuery Executes the command defined in the CommandText property against the connection defined in the Connection property for a query that does not return any rows (an UPDATE, DELETE or INSERT).Returns an Integer indicating the number of rows affected by the query. ExecuteReader Executes the command defined in the CommandText property against the connection defined in the Connection property. Returns a "reader" object that is connected to the resulting rowset within the database, allowing the rows to be retrieved. ExecuteScalar Executes the command defined in the Command Text property against the connection defined in the Connection property. Returns only a single value.