PHP: Better way to create multi-dimensional arrays?

Question

I'm pulling data from the DB in this format:

Array
(
    [id] => 1
    [exerciseid] => 127
    [date] => 2013-06-12 00:00:00
    [time] => 40271
    [weight] => 
    [distance] => 1000
    [reps] => 
    [intensity] => 
)
Array
(
    [id] => 2
    [exerciseid] => 127
    [date] => 2013-06-12 00:00:00
    [time] => 120813
    [weight] => 
    [distance] => 1000
    [reps] => 
    [intensity] => 
)

Now I want to merge these arrays and create multi-dimensional arrays if the exerciseid's match. I've done this:

Array
(
    [127] => Array
        (
            [1] => Array
                (
                    [time] => 40271
                    [weight] => 
                    [distance] => 1000
                    [reps] => 
                    [intensity] => 
                )

            [2] => Array
                (
                    [time] => 120813
                    [weight] => 
                    [distance] => 1000
                    [reps] => 
                    [intensity] => 
                )

        )

)

My question is, is there a better way to write this than what I have?

    while($e = $db->fetch()) {
        foreach ($e as $key => $value) {

            if($key == 'id')
                $id = $value;

            else if($key == 'exerciseid')
                $exerciseid = $value;

            else if($key == 'time')
                $time = $value;

            else if($key == 'weight')
                $weight = $value;

            else if($key == 'distance')
                $distance = $value;

            else if($key == 'reps')
                $reps = $value;

            else if($key == 'intensity')
                $intensity = $value;

        }

        $a[$exerciseid][$id]['time'] = $time;
        $a[$exerciseid][$id]['weight'] = $weight;
        $a[$exerciseid][$id]['distance'] = $distance;
        $a[$exerciseid][$id]['reps'] = $reps;
        $a[$exerciseid][$id]['intensity'] = $intensity;

    }

wow! thats a lot of IF ELSE blocks better do it in switch Case :) — Þaw
– Þaw, Commented Jun 14, 2013 at 8:54
Did you try while($e = $db->fetch()) { $a[$e['exerciseid']][] = $e; } ? That's an one-liner that does the same thing. — Jon
– Jon, Commented Jun 14, 2013 at 8:55
Why can't you take the result GROUP BY 'exerciseid' and simply a lil? — sk8terboi87 ツ
– sk8terboi87 ツ, Commented Jun 14, 2013 at 8:56

Jérôme · Accepted Answer · 2013-06-14 09:10:28Z

2

while ($e = $db->fetch()) {
    $exerciseid = $e['exerciseid'];
    $id = $e['id'];
    $a[$exerciseid][$id] = $e;
}

or shorter :

while ($e = $db->fetch()) {
    $a[$e['exerciseid']][$e['id']] = $e;
}

and if you don't want some keys, use unset() to remove them :

while ($e = $db->fetch()) {
    $exerciseid = $e['exerciseid'];
    $id = $e['id'];
    unset($e['id']);
    unset($e['exerciseid']);
    unset($e['date']);
    $a[$exerciseid][$id] = $e;
}

edited Jun 14, 2013 at 9:10

answered Jun 14, 2013 at 8:59

Jérôme

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Comments

deceze · Accepted Answer · 2013-06-14 08:55:09Z

1

$a[$e['exerciseId']][$e['id']] = array_diff_key($e, array_flip(array('exerciseId', 'id', 'date')));

If you're assigning the same array to another array, do $a = $b.
If you only want some select keys, use array_intersect_key.
If you want to omit certain keys, use array_diff_key.

answered Jun 14, 2013 at 8:55

deceze♦

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2 Comments

DevZer0 Over a year ago

your missing date in your array_flip

Jérôme Over a year ago

I voted for your answer because it is way much shorter even if it is less readable. Also the array_diff_key - array_flip trick is more advanced PHP scripting in my opinion. Maybe a little hard to understand but very elegant to a purist.

Mmmh mmh · Accepted Answer · 2013-06-14 09:03:25Z

0

while($e = $db->fetch()) {
    foreach(array('time','weight','distance','reps','intensity') as $k){
        $a[$e['exerciseid']][$e['id']][$k] = $e[$k];
    }
}

edited Jun 14, 2013 at 9:03

answered Jun 14, 2013 at 8:57

Mmmh mmh

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Comments

Krishnarag · Accepted Answer · 2013-06-14 09:49:02Z

0

Try this

function groupbyId(&$items,$group_by_key)
{        
    $newkey=0;
    $grouparr   = array();
    foreach ($items as $key => $val)
    {
          $grouparr[$val[$group_by_key]][$newkey]=$val; 
           $newkey++;       
    }  
    return $grouparr;  
}
$grouparr = groupbyId($items,"exerciseid");
print_r($grouparr);

edited Jun 14, 2013 at 9:49

answered Jun 14, 2013 at 9:40

Krishnarag

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