Array
(
    [0] => Array
        (
            [p_id] => 1
            [test_id] => 1
            [test_row] => 1
            [answer_1] => +
            [answer_2] => +
            [answer_3] => -
        )

    [1] => Array
        (
            [p_id] => 2
            [test_id] => 1
            [test_row] => 2
            [answer_1] => +
            [answer_2] => +
            [answer_3] => +
        )
     ....

    [570] => Array
        (
            [p_id] => 3
            [test_id] => 1
            [test_row] => 3
            [answer_1] => +
            [answer_2] => +
            [answer_3] => o
        )

{
    test_id_1: {
        row_1: {
            a: +,
            b: o,
            c: -,
        }
        row_2: {
            a: +,
            b: +,
            c: -,
        }
        row_3: {
            a: o,
            b: o,
            c: +,
        }
    },
    test_id_38: {
        row_1: {
            a: -,
            b: -,
            c: +,
        }
        row_2: {
            a: +,
            b: +,
            c: -,
        }
        row_3: {
            a: +,
            b: o,
            c: +,
        }
    }
}