Re: [GENERAL] How I can read-back a serial value just inserted?

[Madison Kelly]

dfx wrote:
Dear Sirs,
my question is very simple:
when I insert a row whith a serial field, a value is automatically
generated; how  can I know this value, strictly of my row, without the risk
of to read the value of another subsequent insertion?

Thank you.

Domenico

Hiya,

  Not sure if it will help you, but what I do is:

SELECT nextval('pt_seq'::regclass);

Take the returned value and use it in the INSERT statement. So for 
example, with the sequence/table:

CREATE SEQUENCE pt_seq
        START WITH 1
        INCREMENT BY 1
        NO MAXVALUE
        NO MINVALUE
        CACHE 1;
ALTER TABLE pt_seq OWNER TO digimer;

CREATE TABLE part_type (
        pt_id   int     primary key     default(nextval('pt_seq')),
        pt_name text,
        ...
);
ALTER TABLE part_type OWNER TO digimer;

I would do (in perl, but other languages should be similar enough):

my $pt_id=$dbh->selectrow_array("SELECT nextval('pt_seq'::regclass)");
$dbh->do("INSERT INTO part_type (pt_id, pt_name...) VALUES ($pt_id, 
'$name'...)");

Hope that helps!

Madi

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