PHP convention in retrieving results indexed by a particular column? - php

Question

I often need to retrieve results and access them by a given column.
Is there a way to write this without walking through the whole dataset each time?
I looked into various PDO fetch modes, but nothing jumped out as being simpler than that. Thanks.
function get_groups() {
$stmt = $dbc->prepare("SELECT * FROM groups ORDER BY group_name");
$stmt->execute();
$groups = $stmt->fetchAll();
$return = [];
foreach($groups as $group) {
$return[$group['id']] = $group;
}
return $return;
}

Answer 1

My proposed solution was pretty obsolete. The right solution comes from this answer
$stmt = $pdo->query("SELECT foo,baz FROM bar")
$groupedByFooValuesArray = $stmt->fetchAll(\PDO::FETCH_GROUP|\PDO::FETCH_UNIQUE)
to group it by another column, change the first column you select
if your goal is to have your same array indexed by different column values, I think the only option is to actually index them by different column values.
you can do that by controlling by which field the array is returned
function get_groups($sql,$key,$values='') {
if ($values != '') {
$stmt = $dbc->prepare($sql);
$stmt->execute($values);
$rows = $stmt->fetchAll(PDO::FETCH_ASSOC);
}
else {
$rows = $dbc->query($sql)->fetchAll(PDO::FETCH_ASSOC);
}
foreach ($rows as $row) {
$indexed[$row[$key]] = $row;
}
return $indexed;
}
then, use get_groups to build an indexed array:
$sql = 'SELECT * FROM groups ORDER BY group_name'
var_dump(get_groups($sql,'id'));
There might be a way to store a resultset in some way that you can fetchAll() it multiple times, that would be awesome. but I don't know it.