pgsql-general-owner@postgresql.org wrote on 08/14/2008 01:21:26 AM:
> Hello. > > I create a table: > > CREATE TABLE groups ( > group_id serial PRIMARY KEY, > name varchar(64) UNIQUE NOT NULL, > guests integer[] DEFAULT '{}' > ) > > I add a new record to the table: > > INSERT INTO groups (name) VALUES ('My friends'); > > Now the table contains 1 record: > > | group_id | name | guests > +----------+------------+-------- > | 1 | My friends | {} > > I read the new record from the table using DBI: > > my $sth = $dbh->prepare(qq/SELECT * FROM groups/); > $sth->execute(); > my (@guests, $group); > push(@guests, $group) while $group = $sth->fetchrow_hashref(); # Line 4 > print $guests[0]->{guests}->[0]; # Why ({group_id=>1, name=>'My friends', > guests=>[0]}) ? > > Output of the script: > > Argument "" isn't numeric in null operation at ./guestmanager.pl line 4 > 0 > > DBD should return a reference to an empty array. But DBD returned > the reference to the array containing 1 element (0). How can I have > a different result: > > ({group_id=>1, name=>'My friends', guests=>[]}) > > PS > Version of DBD::Pg is 2.9.0 .
This can't be the whole program, since you show line 4 (per the error message), which is marked as line 4, but you never connected to the database. Also, I would put parentheses around the expression in the while, to make sure the precedence is what you think it is.
I have a slightly different DBD::Pg version, so I can't test it exactly. Does your version support array types? I don't think mine does (older version).
Susan
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