On Sat, 20 Mar 2010 08:07:01 -0700, Abki
wrote:

Doubble qoutes, null or space are all diffrent.
Double qoutes means the field have data with binary zero. (asci x'00')
Space means field have data as space not binary zero but code X'20' in asci.
Nulls is not represented in data field. Its indicated that field isnt
initiated.

You're correct about NULL but mistaken otherwise. A text value of "" is an
empty string - a String of zero length. It does not contain a binary zero; and
(unless you go to a good bit of effort) Access will trim trailing blanks, so
you cannot store an x'20' alone in a table field. It will be truncated to an
empty string "" if the field's Allow Zero Length property is true, and to NULL
if it isn't.
--

John W. Vinson [MVP]