Re: null values in a view

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От Achilleas Mantzios
Тема Re: null values in a view
Дата
Msg-id 201110051730.10161.achill@matrix.gatewaynet.com
обсуждение исходный текст
Ответ на null values in a view  (Lauri Kajan <lauri.kajan@gmail.com>)
Список pgsql-general
try:

CREATE OR REPLACE VIEW view1 AS
SELECT
  name as a1,
  null::text as a2,
  'test'::text as a3
FROM
  some_table;

Στις Wednesday 05 October 2011 17:22:21 ο/η Lauri Kajan έγραψε:
> Hi all,
>
> How could I create a view that returns null values among all other values.
> Here is a sample that i want to achieve:
>
> CREATE VIEW view1 AS
> SELECT
>   attribute1 as a1,
>   null as a2
> FROM
>   table;
>
> Now the problem is that I got an warning:  column "a2" has type "unknown"
> I know that I should define a data type for a field a2. But how?
> This works with other values but not with nulls:
>
> CREATE VIEW view1 AS
> SELECT
>   attribute1 as a1,
>   text null as a2,
>   text 'test' as a3
> FROM
>   table;
>
>
>
> Thanks
>
> -Lauri Kajan
>



--
Achilleas Mantzios

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