#!/usr/bin/perl
use strict;
use warnings;

use DBI;

my @tables = qw(simple complexer);

my $dbh=DBI->connect("dbi:Pg:;port=2225","","")
    or die "Couldn't connect.";

foreach my $table (@tables) {
    my @key_column_names=$dbh->primary_key(undef, "public",$table);
    print "PK column(s): ", join(", ", @key_column_names), ".\n";
    my $sth=$dbh->primary_key_info( undef, "public", $table, {pg_onerow=>2});
    if (defined $sth) {
        my $pk = $sth->fetchall_arrayref()->[0];
        print "Table $pk->[2] has a primary key on these columns:\n";
        for (my $x=0; defined $pk->[3][$x]; $x++) {
            print "Column: $pk->[3][$x]  (data type: $pk->[6][$x])\n";
        }
    }
}
$dbh->disconnect();