Here is an example of obtaining a custom set of select columns using Propel Criteria, as opposed to using a custom SQL statement. The use of distinct is also demonstrated.

// Set up empty select
$c = new Criteria();
$c->clearSelectColumns();
 
// Read distinct(owningdepot) from the load table...
$c->addSelectColumn(TmsLoadPeer::OWNINGDEPOT);
$c->addGroupByColumn(TmsLoadPeer::OWNINGDEPOT);
$c->setDistinct();
 
// ...which are IN the provided list
$c->add(TmsLoadPeer::LOAD_ID, $loadIds, Criteria::IN);
$depots = TmsLoadPeer::doSelectRS($c);
 
// Then return an array of depots
$arrDep = array();
foreach ($depots as $depot)
{
  $arrDep[] = $depot[0];
}