How to interchange the values of two columns in sql

How to interchange the values of two columns in sql
In this article I'm going to explain how to interchange column values in database table.
In sql server there is no pre defined function for interchange column values.

Example:

First we need to create simple table and then we need to insert some values to that table.
and then we are going to update that table. that's it.

	
Create Sample table:

Create table Sample(EmpID int, firstname nvarchar(100),lastname nvarchar(100))

Insert some values to Sample table:

Insert into Sample values (1,'nathan','rengan')
Insert into Sample values (2,'k','kumar')
Insert into Sample values (3,'Sachin','kumar')
Insert into Sample values (4,'Sachin2','kumar2')

Insert into Sample values (5,'Sachin4','kumar3')

Before Interchange the column values Records will display like this 


1	nathan	rengan
2	k	kumar
3	Sachin	kumar
4	Sachin2	kumar2
5	Sachin4	kumar3


This is very simple task, you need to write simple update query like this 

update Sample set firstname =lastname ,lastname =firstname 


After run above query the result will look like as follows

Select * from Sample


1	rengan	nathan
2	kumar	k
3	kumar	Sachin
4	kumar2	Sachin2
5	kumar3	Sachin4