Обсуждение: add a constraint to specify NOT NULL values

Hi all;

How could I add a constraint to specify that a column can't be null? I've
tried a lot of sintaxis of the style of:

(the table is "pluviometria", and the column is "year")


 ALTER TABLE pluviometria ALTER year CONSTRAINT NOT NULL;
 ALTER TABLE pluviometria.year CONSTRAINT NOT NULL;
 ALTER pluviometria.year ADD CONSTRAINT NOT NULL;
 ALTER TABLE pluviometria ALTER COLUMN cod_variable SET NOT NULL;
 ...
but none works.

Best wishes

Javier

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On Tue, 20 May 2003, javier garcia - CEBAS wrote:

> Hi all;
>
> How could I add a constraint to specify that a column can't be null? I've
> tried a lot of sintaxis of the style of:
>
> (the table is "pluviometria", and the column is "year")
>
>
>  ALTER TABLE pluviometria ALTER year CONSTRAINT NOT NULL;
>  ALTER TABLE pluviometria.year CONSTRAINT NOT NULL;
>  ALTER pluviometria.year ADD CONSTRAINT NOT NULL;
>  ALTER TABLE pluviometria ALTER COLUMN cod_variable SET NOT NULL;

The last form should work if you're using a new enough version (assuming
cod_variable is the column you want to not null - you used year in the
other examples), what version are you using?

A fallback position might be something like
ALTER TABLE pluviometria ADD CHECK (column is not null);