Buy the same token, some application have no use whatsoever for the
distinction between NULL and ''. In that case, the distinction just
adds work.
I would love to see different ways to handle NULL implemented by the
server. For what I do, NULL could always compare equal to zero and ''.
I have no use for NULL in text values. I do need it for numerics,
however it doesn't mean "unknown", it just means "not entered", which is
different because I always treat it as zero.
I haven't put enough thought into this to make any sort of comprehensive
proposal, but it occurs to me that perhaps it could be integrated into
the type system. If I were able to specify, for any given type, a value
that should compare equal to NULL ('' for varchar, 0 for int4, for
example), that, in combination with NOT NULL constraints, might just do
it for me.
-Glen
Well, your mileage must vary. The absence of nulls would make my life
difficult.
Just substitute "unknown" for "null" as mentioned above and the various
operations with "null" make sense. For example, take some days and
low-temperatures:
Mon: 30
Tue: 10
Wed: 0
Thu: unknown
Fri: 0
Sat: unknown
Sun: -5
Was the low temperature the same on:
Mon/Tue: no
Wed/Fri: yes
Thu/Fri: unknown
Thu/Sat: unknown <- the always seemingly confusing null=null is null.
