Null Value

[lkrznchc]

I know this may be a stupid question, but in VBA does Null mean blank? I am looking at using the logic IsNull and am wondering if that is the same logic as =IsBlank() for a cell formula.

 

[Firefly2012]

Use isEmpty:

If IsEmpty(Range("A1").Value) Then '...

 

[Fazza]

FWIW, to test for an empty cell I use
if len(range("a1").value)=0 then

 

[shg]

Cells on worksheets never contain Null -- the VarType of the Value2 property is either vbString, vbDouble, vbBoolean, vbError, or vbEmpty.

Len(range("a1").value)=0 does not distinguish between an empty cell and a cell that contains a null string.

 

[Fazza]

Thanks, shg, I didn't know that.

 

[Fazza]

So, when queries return nulls these are considered vbEmpty?

I always think of these as worksheet cells that contain nulls. As far as the query/table is concerned, they are nulls.

 

[shg]

So, when queries return nulls these are considered vbEmpty?

Sorry, I don't understand the question.

 

[Fazza]

Sorry, I was not clear. In fact I'd strayed off the topic.

The thread was about nulls in VBA. You commented cells on worksheets never contain Null.

I was thinking in a different sphere - I run many queries [database type queries such as via ADO or MS Query, I guess even pivot tables] and have the results in worksheet cells. The queries return nulls: these end up with blank worksheet cells returned from the query. To me these are nulls in worksheet cells but I see now that is only in respect of the query. In the VBA context these are, as you say, not null. They test as vbEmpty. In the context of a query, I can query them and return them using a "field Is Null" criteria.

regards

 

[shg]

I don't do queries to speak of, so I don't know; IIRC, you're a wizard at them.

A Variant can have the value Null, but it has to be assigned (an uninitialized Variant is Empty). I expect that's a meaningful result for a query that returns nothing; "no valid data"

 

[Fazza]

cheers

Just noticed out post counts. You're at 9993, this will be 6992 for me. Congrats in advance on the 10000 post milestone