$q = Heap::construct('HeapAccount')->getQuery();
$qparams = array(
  'status' => HeapAccount::Active,
  'roles' => 'enseignant',
);
$q->where($qparams);
Heap::log($q->toSql());

[MilleJoursProfilController.php:113]
SELECT idx.id,idx.slug,idx.time_created,idx.time_modified,idx.status,idx.publish_start,idx.publish_end,idx.latitude,idx.longitude,idx.profile_id,idx.username,idx.email,idx.roles,idx.code,idx.last_login,idx.dashboard
FROM HeapAccount AS idx
WHERE ((idx.status = 'A') AND (idx.roles = 'enseignant'))

$q = Heap::construct('HeapAccount')->getQuery();
$qparams = array(
  'status' => HeapAccount::Active,
  'roles' => array('enseignant'),
);
$q->where($qparams);
Heap::log($q->toSql());

[MilleJoursProfilController.php:113]
SELECT idx.id,idx.slug,idx.time_created,idx.time_modified,idx.status,idx.publish_start,idx.publish_end,idx.latitude,idx.longitude,idx.profile_id,idx.username,idx.email,idx.roles,idx.code,idx.last_login,idx.dashboard
FROM HeapAccount AS idx
WHERE ((idx.status = 'A') AND (idx.roles = 'a:1:{i:0;s:10:\"enseignant\";}'))