Re: HELP

On Wed, Mar 30, 2005 at 10:53:14PM +0200, Juanky Moral wrote:
> Los valores NULL no son tenidos en cuenta por los operadores SQL
> (lógicos, aritméticos, de comparación, orden, etc).

????

alvherre=# select null is null;
?column?
----------
t
(1 fila)

alvherre=# create table a (a int);
CREATE TABLE
alvherre=# insert into a values (2);
INSERT 17244 1
alvherre=# insert into a values (1);
INSERT 17245 1
alvherre=# insert into a values (null);
INSERT 17246 1
alvherre=# select * from a;
a
---
2
1

(3 filas)

alvherre=# select * from a order by a is null, a;
a
---
1
2

(3 filas)

alvherre=# select * from a order by a is not null, a;
a
---

1
2
(3 filas)

--
Alvaro Herrera (<alvherre[(at)]dcc(dot)uchile(dot)cl>)
"Everybody understands Mickey Mouse. Few understand Hermann Hesse.
Hardly anybody understands Einstein. And nobody understands Emperor Norton."