Checking for a null value

[Sathyaish]

How do you check if a value returned by a DataReader is null or not?
For instance, here's what I wish to check:


If Not Reader.HasRows Then
mPreviousArchivalDate = Nothing
Reader.Close()
Exit Sub
End If

Reader.Read()
If Reader("PreviousArchivalDate") = System.TypeCode.DBNull
Then 'This won't work, so I need a substitute
mPreviousArchivalDate = Nothing
Reader.Close()
Exit Sub
End If
mPreviousArchivalDate =
Convert.ToDateTime(Reader("PreviousArchivalDate"))


The above comparison with TypeCode.DBNull won't work. VB6 had an
IsNull() function in the VBA library. What does ADO.NET provide?

 

[Sathyaish]

*RESOLVED*

I just looked up the IsDBNull() function and that's what I need.

 

[W.G. Ryan MVP]

Glad you got it resolved - but just as an FYI - this is a pretty good
discussion on the subject
http://www.knowdotnet.com/articles/handlingnullvalues.html