$c = $modx->newQuery('Score');
$c->where(array('id' => 5));
$c->fromArray(array(
"myfield" => "this is the new value for myfield",
));
This question has been answered by multiple community members. See the first response.
$c = $modx->newQuery('Score');
$c->where(array('id' => 5));
$score = $modx->getObject('Score', $c);
if ($score) {
$score->fromArray(array(
'myfield' => 'new value for myfield'
));
$score->save();
}$score = $modx->getObject('Score', 5);
if ($score) {
//...
}$score = $modx->getObject('Score', 5);
if ($score) {
$score->set('fieldName', $value);
$score->save();
}