Advanced C# Interview Questions and Answers Part 3

1.) Where is the output of TextWriterTraceListener redirected  ?                           
The output of TextWriteTraceListener Redirected to the console or a text file depending on the parameter passed to the constructor.

2.) Can you change the value of a variable while debugging a c# application ?   
Yes, if you are debugging via visual studio.NET.

3.) What is the service layer in 3 Tier .NET application  ?                                            

• Presentation Layer
• Business Access Layer(BAL)
• Data Access Layer (DAL)

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4.) What is the role of the DataReader class in ADO.NET Connections  ?             

The DataReader class returns a read-only dataset from the datasource when the command is executed.

5.) What is wild character in SQL SERVER  ?                                                                    
The wild character is % in SQL . You can use this symbol with like keyword.
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6.) What is  the thumb rules of transactions ?                                                                   
There are four main property of transactions which is knows as ACID Property.

• Atomic :- It is an unit of work and does not dependent on previous and following transactions.It must be atomic.
• Consistency :- Data should be in consistence form. Means data is either committed or roll back ,not "in-between" case where something has been updated and something has not. 
• Isolation :- It means, no transaction sees the intermediate results of current transaction.
• Durability :-It means,the values persist if the data had been committed even if the system crashes right after.

7.) What type of connection is supported by Microsoft SQL Server ?                       

• Window Authentication
• SQL Server Authentication

8.) What authentication is trusted and which is untrusted ?                                       

• Windows Authentication is trusted because the username and password are checked with the Active Directory.
• The SQL server Authentication is untrusted because SQL Server is the only verified participating in transactions.

9.) What does dispose method do with the connection object ?                                  
It helps to delete it from the memory.

10.) What is a pre-requiste for connection polling  ?                                                       
In connection polling ,multiple process must agree that they will share the same connection where every parameter is the same.

11.) What is delegate  ?                                                                                                                
A delegate encapsulates a references to a method.
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12.) What is trigger   ?                                                                                                                  
A trigger is an event that is automatic executed when condition is satisfied.