SQL schema

1_create_schema.sql

CREATE TYPE transformer_winding AS (voltage NUMERIC(5,1), current NUMERIC(5,3));
CREATE TABLE power_supply_transformer(reference CHAR(6) PRIMARY KEY, pri transformer_winding NOT NULL, secs transformer_winding[] NOT NULL, size_reference VARCHAR(5) NOT NULL);

controller.php

<?php

$loader = require __DIR__."/../vendor/.composer/autoload.php";
$loader->add('YourDb', "/tmp"); // Set yours

use YourDb\PublicSchema\PowerSupplyTransformer;
use YourDb\PublicSchema\PowerSupplyTransformerMap;
use YourDb\PublicSchema\Converter\TransformerWindingConverter;


$database = new Pomm\Connection\Database(array('dsn' => 'pgsql://user:password@host:port/db_name'));
$connection = $database
    ->registerConverter('TransformerWinding', new TransformerWindingConverter(), array('public.transformer_winding'))
    ->getConnection();

$transformers = $connection
    ->getMapFor('YourDb\PublicSchema\PowerSupplyTransformer')
    ->findWhere('array_upper(secs, 1) > 1'); // find only transfo with more than 1 windings on the secondary.

foreach($transformers as $transformer)
{
    printf("%s\n", print_r($transformer, true));
}

/**
YourDb\PublicSchema\PowerSupplyTransformer Object
(
    [fields:protected] => Array
        (
            [reference] => PST044
            [pri] => TransformerWinding Object
                (
                    [voltage] => 220.0
                    [current] => 0.100
                )

            [secs] => Array
                (
                    [0] => TransformerWinding Object
                        (
                            [voltage] => 12.0
                            [current] => 1.000
                        )

                    [1] => TransformerWinding Object
                        (
                            [voltage] => 12.0
                            [current] => 1.000
                        )

                )

            [size_reference] => EI84
        )

    [fields_definition:protected] => Array
        (
            [reference] => String
            [pri] => TransformerWinding
            [secs] => TransformerWinding[]
            [size_reference] => String
        )

    [status:protected] => 1
    [primary_key:protected] => Array
        (
            [0] => reference
        )

)
**/

TransformerWinding.php

<?php

namespace YourDb\PublicSchema\Type;

class TransformerWinding
{
    public $voltage;
    public $current;

    public function __construct($voltage, $current)
    {
        $this->voltage = $voltage;
        $this->current = $current;
    }
}

TransformerWindingConverter.php

<?php

namespace YourDb\PublicSchema\Converter;

use Pomm\Converter\ConverterInterface;
use YourDb\PublicSchema\TransformerWinding;

class TransformerWindingConverter implements ConverterInterface
{
    public function fromPg($data, $type = null)
    {
        $data = trim($data, "()");
        $elts = preg_split('/,/', $data);

        if (count($elts) !== 2)
        {
            throw new Exception(sprintf("Cannot parse winding data '%s'.", $data));
        }

        return new TransformerWinding($elts[0], $elts[1]);
    }

    public function toPg($data, $type = null)
    {
        return sprintf("(%5.1f,%5.3f)", $data->voltage, $data->current);
    }
}