$ perl main.pl 
enter pg pass: 
foo (7/2006-11-20)
DBD::Pg::st execute failed: called with 1 bind variables when 2 are needed [for Statement "SELECT param2, name, param1, description, param4, param5, data2, id, param3
FROM   ppo_data
WHERE  id_attached=? AND date=?
" with ParamValues: 1=undef, 2=undef] at /usr/share/perl5/DBIx/ContextualFetch.pm line 52, <STDIN> line 1.

##</code><code>##

postgresql> CREATE TABLE "indicators" (
  id SERIAL UNIQUE,
  name VARCHAR(20) NOT NULL,
  param1 VARCHAR(10),
  param2 VARCHAR(10),
  param3 VARCHAR(10),
  param4 VARCHAR(10),
  param5 VARCHAR(10),
  description VARCHAR(30),
  PRIMARY KEY (id)
);
postgresql> INSERT INTO indicators VALUES (7, 'PPO', 9, 4, 2, NULL, NULL, 'PPO');
postgresql> CREATE TABLE "ppo_data" (
  id_attached INTEGER,
  date DATE NOT NULL,
  data1 NUMERIC(10, 5) NOT NULL,
  data2 NUMERIC(10, 5),
  PRIMARY KEY (id_attached, date)
);
postgresql> INSERT INTO ppo_data VALUES (7, '20061120', 23, 34);

##</code><code>##

## FOO.pm
package FOO;
use base 'Class::DBI';
my $username = 'hue';
my $password;
my $pgdbhost = 'localhost';
my $pgdbname = 'hue';
sub get_pgdbpass {
    print "enter pg pass: ";
    ## cheap
    system '/bin/stty -echo';
    chomp (my $pgdbpass = <STDIN>);
    system '/bin/stty echo';
    print "\n";
    return $pgdbpass;
}
__PACKAGE__->connection (
    "dbi:Pg:dbname=$pgdbname;host=$pgdbhost;",
    $username,
    $password ? $password : ($password = get_pgdbpass),
    {AutoCommit => 0, RaiseError => 1},
);

1;

##</code><code>##

## FOO/Indicators.pm
package FOO::Indicators;
use base 'FOO';
__PACKAGE__->table ('indicators');
__PACKAGE__->columns (
    All => qw/id name param1 param2 param3 param4 param5 description/
);

1;

##</code><code>##

## FOO/Indicators/PPO.pm
package FOO::Indicators::PPO;
use base 'FOO::Indicators';
__PACKAGE__->table ('ppo_data');
__PACKAGE__->columns (Primary => qw/id_attached date/);
__PACKAGE__->columns (Essential => qw/data1/);
__PACKAGE__->columns (Others => qw/data2/);

1;

##</code><code>##

## main.pl
use warnings;
use strict;

use FOO::Indicators::PPO;
my $foo = FOO::Indicators::PPO->retrieve (id_attached => 7, date => '20061120');
print "foo ($foo)\n";
$foo->delete;
FOO::Indicators::PPO->dbi_commit;