On 20 September 2010 14:53, Carlos Mennens <carlos.mennens@gmail.com> wrote:
> I have a table in my database and would like to modify the one column
> that is already configured to be the PRIMARY KEY but I forgot to set
> it for AUTO_INCREMENT. For some reason I can't find what the proper
> command would be in the documentation and my commands from MySQL don't
> appear to work properly in PostgreSQL:
>
>
> sun=# \d blades
> Table "public.blades"
> Column | Type | Modifiers
> ----------+-----------------------+-----------
> id | integer | not null
> ilom_ip | character varying(15) |
> host_os | character varying(50) |
> host_ip | character varying(15) |
> hostname | character varying(50) |
> serial | character varying(30) |
> gfe | character varying(10) |
> admin | character varying(50) |
> Indexes:
> "blades_pkey" PRIMARY KEY, btree (id)
>
> My command is not working so I don't know what I am doing wrong:
>
> sun=# ALTER TABLE blades MODIFY int AUTO_INCREMENT;
> ERROR: syntax error at or near "MODIFY"
> LINE 1: ALTER TABLE blades MODIFY int AUTO_INCREMENT;
>
That's MySQL syntax. Usually you'd just use the SERIAL datatype which
automatically creates a sequence. But since you've already made the
table, you can create it manually:
CREATE SEQUENCE seq_blades_id;
SELECT setval('seq_blades_id', max(id)) FROM blades; -- set the
sequence's value to the maximum value of "id"
ALTER TABLE blades ALTER COLUMN id SET DEFAULT
nextval('seq_blades_id'); -- make default value get value from
sequence
--
Thom Brown
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