Re: NULL OR ZERO - Mailing list pgsql-hackers

From Andrei Kovalevski
Subject Re: NULL OR ZERO
Date
Msg-id 47A6F407.5080708@commandprompt.com
Whole thread Raw
In response to NULL OR ZERO  ("Omar Bettin" <o.bettin@tiscali.it>)
List pgsql-hackers
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...
>
> ---------------------------(end of broadcast)---------------------------
> TIP 9: In versions below 8.0, the planner will ignore your desire to
>       choose an index scan if your joining column's datatypes do not
>       match


-- 
Andrei Kovalevski
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