Beefy Boxes and Bandwidth Generously Provided by pair Networks
Problems? Is your data what you think it is?
 
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?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others making s'mores by the fire in the courtyard of the Monastery: (13)
As of 2015-03-27 19:55 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    When putting a smiley right before a closing parenthesis, do you:









    Results (619 votes), past polls