[Flow] Delete Entity extends TYPO3 Abstractparty

[Rocky]

Hi,

School extends \TYPO3\Party\Domain\Model\AbstractParty. I tried to code SchoolController's DeleteAction within below code:

public function deleteAction(\Hwwcn\Sponsor\Domain\Model\School $school) {                                         
        foreach ($school->getAccounts() as $account) {   
             $school->removeAccount($account);
        }   
       $this->partyRepository->remove($school);
}

But I got error saying: "SQLSTATE[23000]: Integrity constraint violation: 1451 Cannot delete or update a parent row: a foreign key constraint fails (`dev_flow3`.`typo3_flow_security_account`, CONSTRAINT `typo3_flow_security_account_ibfk_1` FOREIGN KEY (`party`) REFERENCES `typo3_party_domain_model_abstractparty` (`persistence_object_identi)"

Any idea  please?