At 10:22 PM 2/22/2007, Tim Tassonis wrote:
Chris wrote:
An empty string is a KNOWN value. You know exactly what that value
is - it's an empty string.
A NULL is UNKNOWN - it doesn't have a value at all.
I do still think it is a bit of an oddity, the concept of the null
column. From my experience, it creates more problems than it
actually solves and generally forces you to code more rather than
less in order to achieve your goals.
But as it is a fundamental, defined part of the sql standard, one
just has to live with it.
Well it can be useful to have a column like:
foo integer not null default null
That means someone/something must specify a value for foo when doing
an insert. They can't just hope for the best that there's a default...
I think that works on postgresql but not on MySQL (see back on topic :) ).
Have fun!
Link.
