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Thread: not null

not null

From
ryanne cruz
Date:
hi list.

i have a column that has a "not null" as its modifier. is there a way that i
can remove that? or better yet to make it a "serial not null"?

thanks!

ryanne

Re: not null

From
Philipp Ottlinger
Date:
ryanne cruz wrote:
>
> hi list.
>
> i have a column that has a "not null" as its modifier. is there a way that i
> can remove that? or better yet to make it a "serial not null"?
>

It depends on your entitiy-relationship schema - usually it makes sense
to define things as "not null" and it shouldn't be considered to be
taken away just by chance !!!

Usually you can alter the TABLE to remove such constraints ...
SERIAL - if I'm not too mistaken - is automatically maintained by
postgres as an implicit sequence whose values are generated by calling
sequence.nextval autonomously everytime you "need" a value!

Yours,
Phil

Re: not null

From
Matthew Horoschun
Date:
Hi Ryanne,

As already suggested, a SERIAL is just an column that has a default of
the nextval() of an implicitly defined SEQUENCE.

So, try:

ALTER TABLE table_name ALTER COLUMN column_name SET DEFAULT
nextval('column_name_seq'::text);
CREATE SEQUENCE column_name_seq;

Cheers

Matthew.

On Saturday, January 25, 2003, at 10:52  PM, ryanne cruz wrote:

>
> hi list.
>
> i have a column that has a "not null" as its modifier. is there a way
> that i
> can remove that? or better yet to make it a "serial not null"?


--
Matthew Horoschun
Network Administrator
CanPrint Communications Pty. Ltd.


--
Matthew Horoschun
Network Administrator
CanPrint Communications Pty. Ltd.

Mobile:        0417 282 378
Direct:        (02) 6295 4544
Telephone:    (02) 6295 4422
Facsimile:     (02) 6295 4473

Re: not null

From
Matthew Horoschun
Date:
Hi Ryanne,

As already suggested, a SERIAL is just an column that has a default of
the nextval() of an implicitly defined SEQUENCE.

So, try:

ALTER TABLE table_name ALTER COLUMN column_name SET DEFAULT
nextval('column_name_seq'::text);
CREATE SEQUENCE column_name_seq;

Cheers

Matthew.

On Saturday, January 25, 2003, at 10:52  PM, ryanne cruz wrote:

>
> hi list.
>
> i have a column that has a "not null" as its modifier. is there a way
> that i
> can remove that? or better yet to make it a "serial not null"?


--
Matthew Horoschun
Network Administrator
CanPrint Communications Pty. Ltd.


--
Matthew Horoschun
Network Administrator
CanPrint Communications Pty. Ltd.

Mobile:        0417 282 378
Direct:        (02) 6295 4544
Telephone:    (02) 6295 4422
Facsimile:     (02) 6295 4473