Beefy Boxes and Bandwidth Generously Provided by pair Networks
good chemistry is complicated,
and a little bit messy -LW
 
PerlMonks  

Re^2: "undef" is not NULL and what to do about it

by herveus (Parson)
on Feb 25, 2013 at 20:28 UTC ( #1020563=note: print w/replies, xml ) Need Help??


in reply to Re: "undef" is not NULL and what to do about it
in thread "undef" is not NULL and what to do about it

Howdy!

NULL as used in relational databases still carries semantic ambiguity.

It could indicate that the value is absent, or it could indicate that the value is unknown. Or it could mean either. If I recall correctly, Codd called for multiple flavors of NULL.

yours,
Michael
  • Comment on Re^2: "undef" is not NULL and what to do about it

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://1020563]
help
Chatterbox?
[Corion]: LanX: Broken links in what sense?
[Discipulus]: neurocent goes always up with the same curve of population raise
[marto]: believe in derp coin
[Corion]: Oh - I see ...
[LanX]: like http://cb60. datenzoo.de/:// perlmonks.org/ index.pl?node_id= 1215217
[Discipulus]: username links i bet
[Corion]: (also, let me recommend https://mini-cb60. datenzoo.de/ over that, as it has https :)
[LanX]: all links
[Corion]: I guess I should make the certificate valid for both hostnames
[LanX]: and broken links ;p

How do I use this? | Other CB clients
Other Users?
Others taking refuge in the Monastery: (8)
As of 2018-05-25 15:58 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?
    Notices?