/**
  * Sets the value of the specified property on this TenantObjectInstance.
  * @param unknown $property
  * @param unknown $value
  * @return boolean
  * @see TenantObjectInstanceProperty
  */
 public function SetPropertyValue($property, $value)
 {
     global $MySQL;
     if (is_string($property)) {
         $property = $this->ParentObject->GetInstanceProperty($property);
     }
     if ($property == null) {
         return false;
     }
     $query = "INSERT INTO " . System::$Configuration["Database.TablePrefix"] . "TenantObjectInstancePropertyValues (propval_InstanceID, propval_PropertyID, propval_Value) VALUES (";
     $query .= $this->ID . ", ";
     $query .= $property->ID . ", ";
     $query .= "'" . $MySQL->real_escape_string($property->Encode($value)) . "'";
     $query .= ")";
     $query .= " ON DUPLICATE KEY UPDATE ";
     $query .= "propval_PropertyID = values(propval_PropertyID), ";
     $query .= "propval_Value = values(propval_Value)";
     $result = $MySQL->query($query);
     if ($result === false) {
         return false;
     }
     return true;
 }