Re: empty string == NULL

The "trinary" logic of having True, False, and Null goes back to Codd's original article on relational databases. I suspect that the only way it will get changed is if it is explicitly banned in the ANSI SQL standard.

If I remember Codd rationale for NULL was that there is no way of knowing what an empty column contains and therefore rows containing nulls in columns being used to qualify candidates for selection should be ignored.

You can always use the NVL function to convert NULL into whatever you feel is appropriate -- and the fact that any two developers might not agree as to what is appropriate tends to prove that Codd's theoretical approach is really quite practical

hth

Andreas Steidle wrote:

> From the oracle doc:
>
> Do not use null to represent a value of zero, because they are not
> equivalent. (Oracle currently treats a character value with a length of zero
> as null. ... [1])
>
> Is there a workround for this contardictory semantik garbage? A string is a
> string, even if it's empty!!! Perhaps some env-var??
> In other words: Is there a way to make Oracle remember a '' and NOT convert
> it to NULL ???
>
> thanx, Andreas
>
> [1] However, this may not continue to be true in future releases, and Oracle
> recommends that you do not treat empty strings the same as NULLs.
>
> Hope this will happen very soon as default behavoir.

--
Once I figured out how to spell DBA I became one -- Jerry Gitomer Received on Wed Dec 22 1999 - 23:34:23 CST