/**
* Gets the name of the single id field. Note that this only works on
* entity classes that have a single-field pk.
*
* @return string
* @throws MappingException If the class has a composite primary key.
*/
public function getSingleIdentifierFieldName()
{
if ($this->isIdentifierComposite) {
throw MappingException::singleIdNotAllowedOnCompositePrimaryKey($this->name);
}
return $this->identifier[0];
}
