CHECK FOR NULL IN VB

Question

I am trying to identify a NULL value in a string field and assign a value.

IsNull = True is causing an error.

Any other suggestions?

EllenTejan · Answer

Thank you don

I imbeded

isNull(ROAD) = True

into  my expression and it worked for me.

Ellen

JohnHauck · Answer

Please use the following:

Dim ROAD as String
If IsNull( [ROAD_NAME]) Then
ROAD = "NONE"
Else
ROAD = [ROAD_NAME] 
End If

JamesCrandall · Answer

Not familiar with ModelBuilder, but the VB.NET function to check for null values is the IsDBNull function.  Maybe something like this? (although I am not sure about getting/setting your "[ROAD_NAME]" value):Dim ROAD As String
If Not IsDBNull([ROAD_NAME]) Then
  ROAD = [ROAD_NAME]
Else
  ROAD = "NONE"
End If

I am using ModelBuilder and have the following:

Dim ROAD as String
ROAD = [ROAD_NAME]

if isNull(ROAD) = True then
ROAD = "NONE"
End If