[thelist] Null Value from a database to a string?

Peter Brunone (EasyListBox.com) peter at easylistbox.com
Wed Dec 29 20:16:45 CST 2004

	I never bother checking for nulls; if there's a field that could
potentially be null, I just string it as a matter of practice:


-----Original Message-----
From: thelist-bounces at lists.evolt.org On Behalf Of David Travis

Hi Casey,

You should have something like this:

Dim adrs2 as String
If TypeOf myRow["adrs2"] Is DbNull Then
	adrs2 = String.Empty
	adrs2 = myRow["adrs2"].ToString()
End If

I am writing this code without testing it, and it was a while since I
worked with VB.NET, so I am not sure this is 100% working, but that's
the main idea.

Good Luck!
David Travis.

-----Original Message-----
From: thelist-bounces at lists.evolt.org On Behalf Of Casey Crookston

asp.net in vb...

I'm populating a form from a database row.  There's a column in the db
for address and address2 incase the user needs a second line for their
address. In the db address2 is allowed a null value, but when trying to
populate the form I get this error:

Cast from type 'DBNull' to type 'String' is not valid.
Description: An unhandled exception occurred during the execution of the
current web request. Please review the stack trace for more information
about the error and where it originated in the code.

Exception Details: System.InvalidCastException: Cast from type 'DBNull'
to type 'String' is not valid.

Source Error:

Line 95:   baddress2.text=mySingleMemberDtr("b_address2")

Makes sense, I guess.  It won't let a null value be passed into a text
string.  What can I do to allow a null value to be entered. I REALLY
don't want to have to force the user to enter something like "n/a" into
the field if it is empty.  Or, what's the best way to have a value look
empty when it's not?


More information about the thelist mailing list