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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


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