/**
  * Find object by primary key.
  * Propel uses the instance pool to skip the database if the object exists.
  * Go fast if the query is untouched.
  *
  * <code>
  * $obj  = $c->findPk(12, $con);
  * </code>
  *
  * @param mixed $key Primary key to use for the query
  * @param     PropelPDO $con an optional connection object
  *
  * @return   ProductArchive|ProductArchive[]|mixed the result, formatted by the current formatter
  */
 public function findPk($key, $con = null)
 {
     if ($key === null) {
         return null;
     }
     if (null !== ($obj = ProductArchivePeer::getInstanceFromPool((string) $key)) && !$this->formatter) {
         // the object is already in the instance pool
         return $obj;
     }
     if ($con === null) {
         $con = Propel::getConnection(ProductArchivePeer::DATABASE_NAME, Propel::CONNECTION_READ);
     }
     $this->basePreSelect($con);
     if ($this->formatter || $this->modelAlias || $this->with || $this->select || $this->selectColumns || $this->asColumns || $this->selectModifiers || $this->map || $this->having || $this->joins) {
         return $this->findPkComplex($key, $con);
     } else {
         return $this->findPkSimple($key, $con);
     }
 }
 /**
  * Retrieve a single object by pkey.
  *
  * @param int $pk the primary key.
  * @param      PropelPDO $con the connection to use
  * @return ProductArchive
  */
 public static function retrieveByPK($pk, PropelPDO $con = null)
 {
     if (null !== ($obj = ProductArchivePeer::getInstanceFromPool((string) $pk))) {
         return $obj;
     }
     if ($con === null) {
         $con = Propel::getConnection(ProductArchivePeer::DATABASE_NAME, Propel::CONNECTION_READ);
     }
     $criteria = new Criteria(ProductArchivePeer::DATABASE_NAME);
     $criteria->add(ProductArchivePeer::ID, $pk);
     $v = ProductArchivePeer::doSelect($criteria, $con);
     return !empty($v) > 0 ? $v[0] : null;
 }