What do you understand by Asynchronous Database Commands ?

When we execute any database. Thread that executing the command waits before the command get fully executing before executing any additional code. Thread is blocked for another process. But Asynchronous Database Commands solve this problem when database command is executing the current thread can continue on other process.Thread can execute a no of database command.

There are two benefits of using Asynchronous Database Commands.
1) Executing Multiple Databse Commands simultaneously improve performance.
2) Because ASP.Net framework uses a limited pool service for request. Whenany request for a page is comes its assign a thread to handle the request. If framework is out of thread then job is in gueses we get error 503. But if we are using asynchronous database command then current thread is release back to current thread pool.

How will you get result from two table in SqlDataReader ?

Syntax:

string str="Select * from table1;Select * from table2";
cmd.commandtext=str;
dr=cmd.executereader();

What is the difference in using IP address and DNS name in the connection string while connecting to SQL database?

When we are making connection string always use Server's IP address not the DNS name if we use IP address it will reduce the time taken for connection to establish.

Because server IP address is used to get a default or named instance of Sql Server that ls running. if we are running the cluster we have to use the Virtual SQL Server IP address.

What are the differences between Datalist DataGrid and datarepeater ?

DataList

* Has table appearance by default
* Has no auto format option
* has no default paging & sorting options
* can define separators between elements using template

DataGrid

* Has a grid appearance by default
* has a auto format option
* has default paging and sorting
* has no separator between elements

DataRepeater

* simple,read-only output, has no built in support for selecting or editing items, has no default appearance, has no default paging.