Subject Re: [firebird-support] Re: seems bug : Field accepts NULL Values (empty string) even if it is defined w
Author David Johnson
I think that I agree with an earlier post that the use of the word "NULL" was a poor choice for the standard. However, it is a well defined standard with expected behavior across all RDBMS systems. I don't know about relational math, but the real-life practice is very practical and not nearly as awkward as your posts seem to suggest.

There is room for latitude in implementation, but the behaviors of elements (like NULL values) are well defined by a cross platform standard.

Rather than taking this up with the Firebird support list, take it up with ANSI and the ISO, who defined the standard that Firebird implements.

----- Original Message -----
From: Nando Dessena
Sent: Monday, March 22, 2004 9:33 PM
Subject: Re: [firebird-support] Re: seems bug : Field accepts NULL Values (empty string) even if it is defined w

David, all,

D> Just like someone else was stating, if we had been unable to set the fields to
D> NULL, we would've had to have had a separate field for each value we were
D> collecting to declare it's possible NULL state.

the usefulness of having a special value that indicates that a value
is missing is unquestioned. The usefulness of NULL and tri-state
boolean logic as the SQL standard prescribes it is more problematic to
defend. Relational algebra doesn't know what a NULL is. So relational
databases shouldn't have known as well.

Nando Dessena

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