Invalid use of NULL

[battenberg]

Any tips on the following?

against every customer in my DB I have a notes field in the table.

I want to be able to update the [notes] field with a string concatenation based on multiple entries from a form.

my code (simplyfied) is along these lines.

dim strNotes as String
dim strConcatenation as string 

' dim a whole bunch of strings 
' this bit collects a whole bunch of strings 
'that will become the string concatenation (not shown)

Notes.setfocus
strNotes = [Notes]
strNotes = strNotes & " " & strConcatenation
[Notes] = strNotes

however I get the error 'Invalid use of NULL' if the original [notes] is empty to start with.

I have tried to write an if routene for (if strNotes = "") etc... but had no luck

can anyone point me towards the correct way of handling NULL given this scenario.

 

[ejstefl]

You can just say:

[Notes] = [Notes] & " " & strConcatenation

There is no need to assign the value of [Notes] to a variable first.

Of course, if [Notes] is null, there will be an extra leading space. You could use:

[Notes] = ([Notes] + " ") & strConcatenation

if you do not want the extra leading space.

 

[KenHigg]

Something like:

me!myNoteFieldName = me!myNoteFieldName & strNotes

???

 

[battenberg]

Thank you both for your quick and simple replies...

After playing about mostly with VB6 and excel VBA - moving to Access I find it has has a slightly different angle on the way things are done..!

but learning day by day!!!

Thanks again...very Much appreciated!!!

 

[boblarson]

And as a third way, you could modify one line of your original code to:

strNotes = Nz([Notes],"")