Symfony中的外键问题

Question

我遇到此问题，我只能得到错误消息。我有一些学生ID是外键的表，但即使你的ID号码不是任何表格，它仍然给出信息“你不能删除这个学生”，但如果它可以删除将不会通过那里

public function findBystudentid($studentid) 
    { 


    $record= $this->getEntityManager()->getRepository('AcmeDemoBundle:record')->findBy(['studentid' => $studentid]); 
      $lecture = $this->getEntityManager()->getRepository('AcmeDemoBundle:lecture')->findBy(['studentid' => $studentid]); 
      $faculty = $this->getEntityManager()->getRepository('AcmeDemoBundle:faculty')->findBy(['studentid' => $studentid]); 
      if ($record||$lecture||$faculty){ 
         return true; 
        } else { 
         return false; 
        } 
} 

public function deleteAction(Request $request, $studentid) 
    { 
     $form = $this->createDeleteForm($studentid); 
     $form->handleRequest($request); 

     $em = $this->getDoctrine()->getManager(); 
     $deletable = $em->getRepository('AcmeDemoBundle:Student')->findBystudentid($studentid); 

      if ($deletable) { 
       $this->addFlash('error','ERROR! You cannot delete this Student'); 
      } 
      else 
       { 

       $em->remove($deletable); 
       $em->flush(); 
       $this->addFlash('error','Student Deleted'); 
       } 
      return $this->redirect($this->generateUrl('Student')); 

    } 

Answer 1

首先，你的命名是有点过。你需要修复它，因为它往往有点混乱。考虑到这一点，我建议你做这样的：

1.控制器的方法来检查，如果学生是可删除的：

private function isStudentDeletable($studentid) 
{ 
    $em = $this->getEntityManager(); 

    $record= $em->getRepository('AcmeDemoBundle:record')->findBy(['studentid' => $studentid]); 
    if ($record){ 
     return false; 
    } 

    $lecture = $em->getRepository('AcmeDemoBundle:lecture')->findBy(['studentid' => $studentid]); 

    if ($lecture){ 
     return false; 
    } 

    $faculty = $em->getRepository('AcmeDemoBundle:faculty')->findBy(['studentid' => $studentid]); 

    if ($faculty){ 
     return false; 
    } 

    return true; 
} 

2.控制器的动作来调用上述

public function deleteAction(Request $request, $studentid) 
{ 
    $form = $this->createDeleteForm($studentid); 
    $form->handleRequest($request); 

    $deletable = $this->isStudentDeletable($studentid); 

    if (!$deletable) { 
     $this->addFlash('error','ERROR! You cannot delete this Student'); 
    } 
    else 
    { 
     $em = $this->getDoctrine()->getManager(); 
     $student = $em->getRepository('AcmeDemoBundle:Student')->find($studentid) 
     $em->remove($student); 
     $em->flush(); 
     $this->addFlash('error','Student Deleted'); 
    } 

    return $this->redirect($this->generateUrl('Student')); 
} 

希望这个帮助和澄清一点。

Answer 2

我认为你打电话findBystudentid错误，因为findBystudentid不在实体中。

这里是更新的版本

public function deleteAction(Request $request, $studentid) 
{ 
    $form = $this->createDeleteForm($studentid); 
    $form->handleRequest($request); 

    $em = $this->getDoctrine()->getManager(); 
    $deletable = $this->findBystudentid($studentid); 

    if ($deletable) { 
     $this->addFlash('error','ERROR! You cannot delete this Student'); 
    } else { 
     $em->getRepository('AcmeDemoBundle:Student')->findBy(['studentid' => $studentid]) 
     $em->remove($deletable); 
     $em->flush(); 
     $this->addFlash('error','Student Deleted'); 
    } 

    return $this->redirect($this->generateUrl('Student')); 
} 

而且findBystudentid应该是一个私有函数

private function findByStudentId() ...