DotNet Interview Questions - Part 5

DotNet Interview Questions

1) What is the difference between DataSet and DataReader?

2) What is the difference between Class type and Structure type?

3) What are the problems in Multithreading?

4) How will you optimize a query? Hint: Try to explain with Query Execution Plan

5) What is OUTER JOIN, LEFT OUTER JOIN?

6) What Tools you have used in your projects?

7) Discussion on projects undertaken. Try to explain it with following points:-

a) Business need / why you need this kind of software (application)?

b) What are the advantages of using this software (application)?

c) Your Role in the project.

d) Some key challenges that you have faced in this project.

8) Explain Web Services.

9) Explain different validators. What is Range validator?

10) You have to write a stored procedure with three parameters as A (Primary unique key), B, and C. You want to insert these values if A is not present in the table otherwise if A is present you want to update that row with values of B and C in that table. What is the efficient way to do that?

11) What are delegates? Where to use that?

12) What is inheritance? How do you implement it?

13) What is System.Collection? Can you explain Hashtable and Hashcode? What type of keys you can store with Hashtable?

14) What is sealed class?

15) What is Serialization? Which namespace is required for its implementation?Give some practical example ?

16) How do you go for Data retrieval in ADO.NET? Mention different ways for it ? Hint: Mention Connection, command, dataset/datareader, and dataadapter objects.

17) What are WinForms?

18) Can you override static function?

19) Give details of DataSet?

20) Does following code guarantees that Connection will always closed? Or How will you make sure that database connection will always close?

Dim strConnString as String

Dim objConnection as SqlConnection

Dim objCommand as SqlCommand

Dim objReader as SqlDataReader

strConnString = AppSettings.Item(“ConectionString”)

objConnection.ConnectionString = strConnString

objConnection.open()

objCommand = new SqlCommand(“Select FirstName from Employee”)

objCommand.Connection = objConnection

objReader = objCommand.ExecuteReader()

objReader.Close()

objConnection.Close()

21) Suppose we have a set of classes which should log the transaction details in a file. For that purpose we have customized the Log class. To support this functionality which of the following approaches you will choose:-

i) Lets all classes should be derived from Log class.

ii) We will have a separate instance of the Log class which will be used for logging by all other classes.