.net - What should I use to compare DBNull ? Using DBNull.Value or ToString().IsNullOrEmpty()

Question

I can check for a DBnull on a data row using any of the methods.

Either by using

if(dr[0][0]==DBNull.Value)
//do somethin

or by doing

if(dr[0][0].ToString().IsNullOrEmpty())
//do something

In Both Cases I will be getting same result.

But Which one is conecptually right approach. Which was will use less resources

Answer 1

The first way is somewhat correct. However, more accepted way is:

if ( dr[0][0] is DBNull )

And the second way is definitely incorrect. If you use the second way, you will get true in two cases:

1. Your value is DBNull
2. Your value is an empty string