[Tutor] basic gadfly question

[Deirdre Saoirse Moen]

At 9:37 PM +0200 6/11/01, Cynic wrote:
>  >>My questions are these?  Do you have to set all values in the insert
>>>statement or is there some way around this?
>>
>>Gadfly requires this. It is not a constraint of SQL generally.
>>
>>>Is this bad database
>>>programming form to want to set only some fields?  Is this related to gadfly
>>>not supporting Null values?
>
>NULL values are BAD. Learn about SQL, and you'll understand why.

This is *completely* untrue.

In fact, if you actually READ Codd & Date, you'll discover why 
supporting null values is a requirement for a truly relational 
database.

Why? Because sometimes there isn't a relationship between a record in 
one entity and another entity. And sometimes there is.

For example, a student relation may have a link to a faculty relation 
only if the student has an advisor. If that student doesn't have an 
advisor, that attribute SHOULD be null.

In a truly relational database, the null value would signify there 
was no relationship, which is correct.

If you don't support nulls, you'd have to create a false value to a 
false record in the other relation, which implies a relationship that 
doesn't in fact exist.

>  >But none are as simple to set up as gadfly.
>
>I have never heard of that, let alone use it, so I do know.

Gadfly is a SQL implementation written entirely in Python and can be 
found at http://www.chordate.com
-- 
_Deirdre    Stash-o-Matic: http://weirdre.com    http://deirdre.net
"Cannot run out of time.... Is infinite time. You... are finite....
Zathrus... is finite. This... is wrong tool!" -- Zathrus