PHP multidimensional to flat array (changing key->value) - php

Question

This is a problem that I come across frequently when using PHP to query mysql data, and I would like to know if there is a more efficient solution. When I only need two columns of data, for instance the columns 'id' and 'price', I prefer this 'flat' format:
array(
id 1 => price 1,
id 2 => price 2,
id 3 => price 3,
...
);
or in json:
[{"id 1":"price 1"},{"id 2":"price 2"},{"id 3":"price 3"}, ...]
And my usual solution is to loop twice, like so:
require_once('server/connection.php');
$info = mysql_query("SELECT id, price FROM table");
$array1 = array();
while ($row = mysql_fetch_assoc($info)) {
$array1[] = array(
'id' => $row['id'],
'price' => $row['price']
);
}
mysql_close($con);
$array2 = array();
foreach ($array1 as $key => $value) {
$array2[$key][$value['id']] = $value['price'];
}
print json_encode($array2);
which does work, but I think this code is too lengthy for its purpose, and there should be a better way -- so that I only have to loop one array. Any suggestions?

Answer 1

You can simplify your loop to this
while ($row = mysql_fetch_assoc($info)) {
$array1[] = array(
'id '.$row['id'] => 'price '.$row['price']
);
}
print json_encode($array1);

Answer 2

$result = array();
while ($row = mysql_fetch_assoc($info)) {
$result[$row['id']] = $row['price'];
}
print_r($result);

Answer 3

require_once('server/connection.php');
$info = mysql_query("SELECT id, price FROM table");
$array1 = array();
while ($row = mysql_fetch_assoc($info))
$array1[$row['id']] = $row['price'];
mysql_close($con);
print json_encode($array1);
NOTE: your $array2 is a two dimensional array. If it works for you, you need to change your javascript code to handle following flat format i.e. the above code produce
[{"id 1":"price 1"},{"id 2":"price 2"},{"id 3":"price 3"}, ...]