Creating An Associative Multi Dimensional Array from loop in PHP

Question

How can I create an array like the following in PHP from a database result set using a loop:

Array
(
    [T] => Array
        (
            [0] => Array
                (
                    [id] => 1
                    [name] => Timer
                )

            [1] => Array
                (
                    [id] => 2
                    [name] => Tub
                )

        )

    [P] => Array
        (
            [0] => Array
                (
                    [id] => 3
                    [name] => Paper
                )

            [1] => Array
                (
                    [id] => 4
                    [name] => Puppy
                )

        )

)

You will notice that the array keys are a letter, which is taken from the 'name' value in the result set. The loop will be something like this:

while($result = $db->fetch($query) {

  $key = $result['name']{0};

  //  your answer  :-)

}

score 7 · Accepted Answer · answered Dec 08 '11 at 20:40

I think something like this should do it:

$sql = 'SELECT id, name FROM table';
$result = mysql_query( $sql);
$answer = array();
while( $row = mysql_fetch_assoc( $result))
{
    $answer[ strtoupper($row['name'][0]) ][] = $row;
}
mysql_free_result( $result);
var_dump( $answer);

OR, to be more specific (if your query is returning more columns than just id and name):

while( $row = mysql_fetch_assoc( $result))
{
    $answer[ strtoupper($row['name'][0]) ][] = array(
        'id' => $row['id'],
        'name' => $row['name']
    );
}

Ahh great, thanks! The part that makes this happen is the extra [] >> $array[$key][] = $result; rather than $array[$key] = $result;. Without that, the previous gets overwritten as we loop. — Billy, Dec 08 '11 at 20:57

score 0 · Answer 2 · answered Dec 08 '11 at 20:43

0

$indexArray = array(); // Array from Example
while($result = $db->fetch($query) {
    $key = $result['name']{0};
    if(!isset($indexArray[$key])) {
        $indexArray[$key] = array();
    }
    array_push($indexArray[$key], $result);
}

answered Dec 08 '11 at 20:43

PseudoNinja

2,846
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score 0 · Answer 3 · answered Dec 08 '11 at 20:48

0

$results = array();
while($result = $db->fetch($query)) {
  $key = strtoupper($result['name'][0]);
  if(!isset($results[$key]))
    $results[$key] = array();
  $results[$key][] = $result;
}

answered Dec 08 '11 at 20:48

connec

7,231
3
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26

Creating An Associative Multi Dimensional Array from loop in PHP

3 Answers3