NULL OR ZERO

On Feb 3, 2008 7:26 PM, Omar Bettin <o.bettin@tiscali.it> wrote:

Probably I am on the wrong place but for me NULL on numbers means 0 or ZERO.
I know about standards...

NULL means unknown value, ZERO is a known value

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Hello,

Omar Bettin wrote:

Probably I am on the wrong place but for me NULL on numbers means 0 or
ZERO.
I know about standards...

You can easily convert NULLs to 0 in your queries - read about COALESCE
function
http://www.postgresql.org/docs/8.0/interactive/functions-conditional.html.
Compare these SELECTs:

CREATE TABLE test (num INTEGER);
INSERT INTO test VALUES (1), (2), (null), (3), (null), (4), (0);

SELECT num FROM test;

SELECT COALESCE(num, 0) FROM test;

but I think that integralism is somewhat wrong.

Omar
a programmer...

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On Feb 3, 2008 7:41 PM, Jaime Casanova <systemguards@gmail.com> wrote:

On Feb 3, 2008 7:26 PM, Omar Bettin <o.bettin@tiscali.it> wrote:

Probably I am on the wrong place but for me NULL on numbers means 0 or ZERO.
I know about standards...

NULL means unknown value, ZERO is a known value

NULL represents absence of a value. You get the UNKNOWN truth value if
you compare NULL with any data value or another NULL (damn you, 3VL!).