Есть вот такой массив, как его склеить в одно по order_id ?

 [0] => Array
        (
            [order_item_id] => 1
            [order_item_name] => Apple iPhone 5S 32Gb Space Gray A1457 (ME432RU/A)
            [order_item_type] => line_item
            [order_id] => 20177
            [meta_id] => 24194
            [post_id] => 20177
            [meta_key] => _billing_country
            [meta_value] => RU
        )

    [1] => Array
        (
            [order_item_id] => 1
            [order_item_name] => Apple iPhone 5S 32Gb Space Gray A1457 (ME432RU/A)
            [order_item_type] => line_item
            [order_id] => 20177
            [meta_id] => 24195
            [post_id] => 20177
            [meta_key] => _billing_first_name
            [meta_value] => Вячеслав
        )

    [2] => Array
        (
            [order_item_id] => 1
            [order_item_name] => Apple iPhone 5S 32Gb Space Gray A1457 (ME432RU/A)
            [order_item_type] => line_item
            [order_id] => 20177
            [meta_id] => 24196
            [post_id] => 20177
            [meta_key] => _billing_last_name
            [meta_value] => Жулев
        )

    [3] => Array
        (
            [order_item_id] => 1
            [order_item_name] => Apple iPhone 5S 32Gb Space Gray A1457 (ME432RU/A)
            [order_item_type] => line_item
            [order_id] => 20177
            [meta_id] => 24197
            [post_id] => 20177
            [meta_key] => _billing_company
            [meta_value] => 
        )