private function walkPropertyExistenceConstraint(QOM\PropertyExistenceInterface $constraint)
 {
     $selectorName = $constraint->getSelectorName();
     $propertyName = $constraint->getPropertyName();
     return sprintf('%s:*', $propertyName);
 }
 /**
  * @param QOM\PropertyExistenceInterface $constraint
  *
  * @return string
  */
 public function walkPropertyExistenceConstraint(QOM\PropertyExistenceInterface $constraint)
 {
     return $this->sqlXpathValueExists($this->getTableAlias($constraint->getSelectorName()), $constraint->getPropertyName());
 }
 /**
  * PropertyExistence ::=
  *   selectorName'.'propertyName 'IS NOT NULL' |
  *   propertyName 'IS NOT NULL'    If only one
  *                                 selector exists in
  *                                 this query
  *
  *   Note: The negation, 'NOT x IS NOT NULL'
  *      can be written 'x IS NULL'
  *
  * @param  QOM\PropertyExistenceInterface $constraint
  * @return string
  */
 protected function convertPropertyExistence(QOM\PropertyExistenceInterface $constraint)
 {
     return $this->generator->evalPropertyExistence($constraint->getSelectorName(), $constraint->getPropertyName());
 }