RE: Counterquestion - is Oracle a He or a She - or an It or a hermaphrodite
- From: "Billy Verreynne (JW)" <VerreyB@xxxxxxxxxxxx>
- To: <oracle-l@xxxxxxxxxxxxx>
- Date: Tue, 2 Aug 2005 09:45:42 +0200
Mark W. Farnham [mailto:mwf@xxxxxxxx] wrote:
> Quite simply, and the most easily understood example I know, some
people
> have no middle name.
Which means a non-existant middle name. No value. In programming terms
that is called a null.
> In that case, the value of the string of that person's middle name
is not
> NULL, but rather the accurate value for the person's middle name is
the empty
> string.
Disagree!
> The value is absolutely known, whereas the NULL value is definitely
not known.
The mistake is the inconsistent way people want to deal with the
string data type.
What values does this data type encompass? Characters. Now suddenly no
character as in "an empty string" is also a character and a valid data
type value? Come on!
How do I render a value from a variable where that value is considered
okay.. except there's no friggen value to render!!
An empty string is not the same as a number that is equal to zero.
Zero is a value. An empty string has *NO* values. Not a single
character. By definition when a variable has no value, it is null. It
does not contain anything from the data type it encompasses. So how
can a variable that does not contain any of its data type
bytes/characters contain a value?
> I don't know a better way to explain it than that.
Well Mark, I in turn cannot understand why people do not seem to grasp
the very fundemental concept of what a null is and what a value is. I
do agree that dealing with NULLs in Oracle using state operators is
not ideal as its easier to deal with NULLs using math operators (and
in most other languages). But I do not agree with the misconception
that an empty string is somehow different from a NULL string.
--
Billy
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