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Thread: ALTER TABLE follow up

ALTER TABLE follow up

From
"Tom Haddon"
Date:
Hi Folks,

A follow up to the ALTER TABLE question last week. I had asked why I was
getting an error message using the ALTER TABLE to add a PRIMARY KEY, and was
told that this wasn't supported in 7.1.x. I've upgraded to 7.2.1 and now
when I use the following SQL:

ALTER TABLE "agency_contact_info" ADD CONSTRAINT "agency_contact_info_pkey"
PRIMARY KEY NOT NULL ("id");

I get an error message saying that "Existing attribute "id" cannot be a
PRIMARY KEY because it is not marked NOT NULL"

How do I mark this as a NOT NULL to avoid the error message. The column in
question is an INT4 field that has been "acquired" through a SELECT INTO
statement. Is there some way that I can specify the qualities (NOT NULL,
etc.) of the fields in a SELECT INTO statements?

Thanks, Tom

_______________________________
Tom Haddon
IT Director
The Better Health Foundation
414 Thirteenth Street, Suite 450
Oakland, CA 94612
(510) 444-5096
www.betterhealthfoundation.org
_______________________________

Re: ALTER TABLE follow up

From
"Christopher Kings-Lynne"
Date:
Hi Tom,

> A follow up to the ALTER TABLE question last week. I had asked why I was
> getting an error message using the ALTER TABLE to add a PRIMARY
> KEY, and was
> told that this wasn't supported in 7.1.x. I've upgraded to 7.2.1 and now
> when I use the following SQL:
>
> ALTER TABLE "agency_contact_info" ADD CONSTRAINT
> "agency_contact_info_pkey"
> PRIMARY KEY NOT NULL ("id");

I have no idea where you got that NOT NULL bit from - it's not in the
manual.  In fact Posgres 7.2 has no sql function for changing the null
status of a column.  You can manually twiddle the catalogs however - make
SURE there's no NULL values in the column first:

UPDATE pg_attribute SET attnotnull = true WHERE attrelid = (SELECT oid FROM
pg_class WHERE relname = 'agency_contact_info') AND attname = 'id';

Now just go:

ALTER TABLE agency_contact_info ADD PRIMARY KEY (id):

Chris

Re: ALTER TABLE follow up

From
"Tom Haddon"
Date:
Hi Chris,

Thanks for that. I have one final question (for the moment).

How do I also alter the id column properties to reflect as below?

DEFAULT nextval('agency_contact_info_id_key'::text)

Is there an SQL query for this, or another manual "twiddle"?

Thanks, Tom

-----Original Message-----
From: Christopher Kings-Lynne [mailto:chriskl@familyhealth.com.au]
Sent: Tuesday, August 06, 2002 7:02 PM
To: Tom Haddon; pgsql-sql@postgresql.org
Subject: RE: [SQL] ALTER TABLE follow up


Hi Tom,

> A follow up to the ALTER TABLE question last week. I had asked why I was
> getting an error message using the ALTER TABLE to add a PRIMARY
> KEY, and was
> told that this wasn't supported in 7.1.x. I've upgraded to 7.2.1 and now
> when I use the following SQL:
>
> ALTER TABLE "agency_contact_info" ADD CONSTRAINT
> "agency_contact_info_pkey"
> PRIMARY KEY NOT NULL ("id");

I have no idea where you got that NOT NULL bit from - it's not in the
manual.  In fact Posgres 7.2 has no sql function for changing the null
status of a column.  You can manually twiddle the catalogs however - make
SURE there's no NULL values in the column first:

UPDATE pg_attribute SET attnotnull = true WHERE attrelid = (SELECT oid FROM
pg_class WHERE relname = 'agency_contact_info') AND attname = 'id';

Now just go:

ALTER TABLE agency_contact_info ADD PRIMARY KEY (id):

Chris

Re: ALTER TABLE follow up

From
"Christopher Kings-Lynne"
Date:
Hi Tom,

ALTER TABLE agency_contact_info ALTER id SET DEFAULT
nextval('agency_contact_info_id_key'::text);

BTW, Postgres 7.3 will have this command:

ALTER TABLE tab ALTER col SET/DROP NOT NULL;

Chris

> -----Original Message-----
> From: Tom Haddon [mailto:tom@betterhealthfoundation.org]
> Sent: Thursday, 8 August 2002 2:31 AM
> To: Christopher Kings-Lynne; pgsql-sql@postgresql.org
> Subject: RE: [SQL] ALTER TABLE follow up
>
>
> Hi Chris,
>
> Thanks for that. I have one final question (for the moment).
>
> How do I also alter the id column properties to reflect as below?
>
> DEFAULT nextval('agency_contact_info_id_key'::text)
>
> Is there an SQL query for this, or another manual "twiddle"?
>
> Thanks, Tom
>
> -----Original Message-----
> From: Christopher Kings-Lynne [mailto:chriskl@familyhealth.com.au]
> Sent: Tuesday, August 06, 2002 7:02 PM
> To: Tom Haddon; pgsql-sql@postgresql.org
> Subject: RE: [SQL] ALTER TABLE follow up
>
>
> Hi Tom,
>
> > A follow up to the ALTER TABLE question last week. I had asked why I was
> > getting an error message using the ALTER TABLE to add a PRIMARY
> > KEY, and was
> > told that this wasn't supported in 7.1.x. I've upgraded to 7.2.1 and now
> > when I use the following SQL:
> >
> > ALTER TABLE " " ADD CONSTRAINT
> > "agency_contact_info_pkey"
> > PRIMARY KEY NOT NULL ("id");
>
> I have no idea where you got that NOT NULL bit from - it's not in the
> manual.  In fact Posgres 7.2 has no sql function for changing the null
> status of a column.  You can manually twiddle the catalogs however - make
> SURE there's no NULL values in the column first:
>
> UPDATE pg_attribute SET attnotnull = true WHERE attrelid =
> (SELECT oid FROM
> pg_class WHERE relname = 'agency_contact_info') AND attname = 'id';
>
> Now just go:
>
> ALTER TABLE agency_contact_info ADD PRIMARY KEY (id):
>
> Chris
>
>