Prob deleting users

CompanyController.php

public function deleteUserAction($id) {
        $em = $this->getDoctrine()->getManager();
        $parentUser = new User();
        $user = $em->getRepository('ACMECompanyBundle:User')->find($id);
        $currentUser = $this->get('security.context')->getToken()->getUser();
        
        if ($id == $currentUser->getId()) {
            return new Response("You cannot delete the current user");
        }
        
        if (!$user) {
            throw $this->createNotFoundException('No user found for id '.$id);
        }      
        
        if ($user->getParentId() != null) {
            $parentUser = $em->getRepository('ACMECompanyBundle:User')->find($user->getParentId());
            $parentUser->removeChildren($user);
            $em->persist($parentUser);
        }
        
        try {
            $em->remove($user);
            $em->flush();
            $msg = "User deleted!";
            $code = "OK";
        } catch (DBALException $e) {
            return new Response($e);
            $msg = "User cannot be deleted!";
            $code = "ERR";
        }
        $response = new Response(json_encode(array('code' => $code, 'msg' => $msg)));
        $response->headers->set('Content-Type', 'application/json');
        return $response;
    }

Role.php

//Role Entity

<?php

namespace ACME\CompanyBundle\Entity;

use ACME\CompanyBundle\Entity\Role;
use ACME\CompanyBundle\Entity\User;
use Doctrine\Common\Collections\ArrayCollection;
use Doctrine\Common\Collections\Collection;
use Symfony\Bridge\Doctrine\Validator\Constraints\UniqueEntity;
use Symfony\Component\Security\Core\Role\RoleInterface;
use Symfony\Component\Validator\Mapping\ClassMetadata;

use Doctrine\ORM\Mapping as ORM;

/**
 * ACME\CompanyBundle\Entity\Role
 *
 * @ORM\Table(name="roles")
 * @ORM\Entity
 */
class Role implements RoleInterface
{
    /**
     * @var integer $id
     *
     * @ORM\Column(name="id", type="smallint")
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    protected $id;

    /**
     * @var string $roleName
     *
     * @ORM\Column(name="role_name", type="string", length=20)
     */
    protected $roleName;
    
    /**
     * @var string $roleAlt
     *
     * @ORM\Column(name="role_alt", type="string", length=35, unique=true)
     */
    protected $roleAlt;
    
    /**
     * @ORM\ManyToMany(targetEntity="User", mappedBy="userRoles", cascade={"persist"})
     */
    protected $users;
    
    public function __construct()
    {
        $this->users = new ArrayCollection();
    }


    /**
     * Get id
     *
     * @return integer 
     */
    public function getId()
    {
        return $this->id;
    }

    /**
     * Set role_name
     *
     * @param string $roleName
     * @return Role
     */
    public function setRoleName($roleName)
    {
        $this->roleName = $roleName;
    
        return $this;
    }

    /**
     * Get role_name
     *
     * @return string 
     */
    public function getRoleName()
    {
        return $this->roleName;
    }

    /**
     * Add users
     *
     * @param User $users
     * @return Role
     */
    public function addUser(User $users)
    {
        $this->users[] = $users;
    
        return $this;
    }

    /**
     * Remove users
     *
     * @param User $users
     */
    public function removeUser(User $users)
    {
        $this->users->removeElement($users);
    }

    /**
     * Get users
     *
     * @return Collection 
     */
    public function getUsers()
    {
        return $this->users;
    }
    
    /**
     * Implementation of getRole for the RoleInterface.
     * 
     * @return string The role.
     */
    public function getRole()
    {
        return $this->getRoleName();
    }

    /**
     * Set role_alt
     *
     * @param string $roleAlt
     * @return Role
     */
    public function setRoleAlt($roleAlt)
    {
        $this->roleAlt = $roleAlt;
    
        return $this;
    }

    /**
     * Get role_alt
     *
     * @return string 
     */
    public function getRoleAlt()
    {
        return $this->roleAlt;
    }
    
    public static function loadValidatorMetadata(ClassMetadata $metadata) {

        $metadata->addConstraint(new UniqueEntity(array(
            "fields" => "roleAlt", 
            "message" => "This role name is already in use"
            )
        ));
    }
}

User.php

//User Entity

<?php

namespace ACME\CompanyBundle\Entity;

use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\Security\Core\User\UserInterface;
use Doctrine\Common\Collections\ArrayCollection;

/**
 * ACME\CompanyBundle\Entity\User
 *
 * @ORM\Table(name="users")
 * @ORM\Entity
 */
class User implements UserInterface
{
    /**
     * @var integer $id
     *
     * @ORM\Column(name="id", type="smallint")
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    protected $id;

    /**
     * @var string $username
     *
     * @ORM\Column(name="username", type="string", length=20, unique=TRUE)
     */
    protected $username;

    /**
     * @var string $password
     *
     * @ORM\Column(name="password", type="string", length=255)
     */
    protected $password;
    
    /**
     * @var string $salt
     *
     * @ORM\Column(name="salt", type="string", length=255)
     */
    protected $salt;

    /**
     * @var string $fullName
     *
     * @ORM\Column(name="full_name", type="string", length=60, unique=TRUE)
     */
    protected $fullName;

    /**
     * @var integer $contactId
     *
     * @ORM\Column(name="contact_id", type="integer")
     */
    protected $contactId;

    /**
     * @var integer $parentId
     *
     * @ORM\Column(name="parent_id", type="smallint", nullable=true)
     */
    protected $parentId;

    /**
     * @var boolean $isActive
     *
     * @ORM\Column(name="is_active", type="boolean")
     */
    protected $isActive;

    /**
     * @var \DateTime $doj
     *
     * @ORM\Column(name="doj", type="date", nullable=TRUE)
     */
    protected $doj;

    /**
     * @var \DateTime $createdAt
     *
     * @ORM\Column(name="created_at", type="datetime")
     */
    protected $createdAt;

    /**
     * @var \DateTime $updatedAt
     *
     * @ORM\Column(name="updated_at", type="datetime", nullable=TRUE)
     */
    protected $updatedAt;

    /**
     * @var \DateTime $lastAccessed
     *
     * @ORM\Column(name="last_accessed", type="datetime", nullable=TRUE)
     */
    protected $lastAccessed;
    
    /**
     * @ORM\ManyToOne(targetEntity="Contact", cascade={"persist", "remove"})
     * @ORM\JoinColumn(name="contact_id", referencedColumnName="id", onDelete="CASCADE")
     */
    protected $contact;
    
    /**
     * @ORM\ManyToMany(targetEntity="Branch", inversedBy="users", cascade={"persist"})
     * @ORM\JoinTable(name="users_branches")
     * 
     * @var ArrayCollection $branches
     */
    protected $branches;
    
    /**
     * @ORM\ManyToMany(targetEntity="Role", inversedBy="users", cascade={"persist"})
     * @ORM\JoinTable(name="users_roles")
     * 
     * @var ArrayCollection $userRoles
     */
    protected $userRoles;
    
    /**
     * @ORM\OneToMany(targetEntity="User", mappedBy="parent", cascade={"persist"})
     */
    protected $children;

    /**
     * @ORM\ManyToOne(targetEntity="User", inversedBy="children")
     * @ORM\JoinColumn(name="parent_id", referencedColumnName="id", onDelete="SET NULL")
     */
    protected $parent;
    
    public function __construct()
    {
        $this->parentId = null; // Default value for column parent_id
        $this->doj = null;
        $this->lastAccessed = null;
        $this->updatedAt = null;
        $this->isActive = true;
        $this->branches = new ArrayCollection();
        $this->userRoles = new ArrayCollection();
        $this->children = new ArrayCollection();
    }


    /**
     * Get id
     *
     * @return integer 
     */
    public function getId()
    {
        return $this->id;
    }

    /**
     * Set username
     *
     * @param string $username
     * @return User
     */
    public function setUsername($username)
    {
        $this->username = $username;
    
        return $this;
    }

    /**
     * Get username
     *
     * @return string 
     */
    public function getUsername()
    {
        return $this->username;
    }

    /**
     * Set password
     *
     * @param string $password
     * @return User
     */
    public function setPassword($password)
    {
        $this->password = $password;
    
        return $this;
    }

    /**
     * Get password
     *
     * @return string 
     */
    public function getPassword()
    {
        return $this->password;
    }
    
    /**
     * Set salt
     *
     * @param string salt
     * @return User
     */
    public function setSalt($salt)
    {
        $this->salt = $salt;
    
        return $this;
    }

    /**
     * Get salt
     *
     * @return string 
     */
    public function getSalt()
    {
        return $this->salt;
    }

    /**
     * Set full_name
     *
     * @param string $fullName
     * @return User
     */
    public function setFullName($fullName)
    {
        $this->fullName = $fullName;
    
        return $this;
    }

    /**
     * Get full_name
     *
     * @return string 
     */
    public function getFullName()
    {
        return $this->fullName;
    }

    /**
     * Set email
     *
     * @param string $email
     * @return User
     */
    public function setEmail($email)
    {
        $this->email = $email;
    
        return $this;
    }

    /**
     * Get email
     *
     * @return string 
     */
    public function getEmail()
    {
        return $this->email;
    }

    /**
     * Set contact_id
     *
     * @param integer $contactId
     * @return User
     */
    public function setContactId($contactId)
    {
        $this->contactId = $contactId;
    
        return $this;
    }

    /**
     * Get contact_id
     *
     * @return integer 
     */
    public function getContactId()
    {
        return $this->contactId;
    }

    /**
     * Set parent_id
     *
     * @param integer $parentId
     * @return User
     */
    public function setParentId($parentId)
    {
        $this->parentId = $parentId;
    
        return $this;
    }

    /**
     * Get parent_id
     *
     * @return integer 
     */
    public function getParentId()
    {
        return $this->parentId;
    }

    /**
     * Set doj
     *
     * @param \DateTime $doj
     * @return User
     */
    public function setDoj($doj)
    {
        $this->doj = $doj;
    
        return $this;
    }

    /**
     * Get doj
     *
     * @return \DateTime 
     */
    public function getDoj()
    {
        return $this->doj;
    }

    /**
     * Set created_at
     *
     * @param \DateTime $createdAt
     * @return User
     */
    public function setCreatedAt($createdAt)
    {
        $this->createdAt = $createdAt;
    
        return $this;
    }

    /**
     * Get created_at
     *
     * @return \DateTime 
     */
    public function getCreatedAt()
    {
        return $this->createdAt;
    }

    /**
     * Set updated_at
     *
     * @param \DateTime $updatedAt
     * @return User
     */
    public function setUpdatedAt($updatedAt)
    {
        $this->updatedAt = $updatedAt;
    
        return $this;
    }

    /**
     * Get updated_at
     *
     * @return \DateTime 
     */
    public function getUpdatedAt()
    {
        return $this->updatedAt;
    }

    /**
     * Set last_accessed
     *
     * @param \DateTime $lastAccessed
     * @return User
     */
    public function setLastAccessed($lastAccessed)
    {
        $this->lastAccessed = $lastAccessed;
    
        return $this;
    }

    /**
     * Get last_accessed
     *
     * @return \DateTime 
     */
    public function getLastAccessed()
    {
        return $this->lastAccessed;
    }

    /**
     * Add branch
     *
     * @param ACME\CompanyBundle\Entity\Branch $branch
     * @return User
     */
    public function addBranch(\ACME\CompanyBundle\Entity\Branch $branch)
    {
        $this->branches[] = $branch;
    
        return $this;
    }

    /**
     * Remove branch
     *
     * @param ACME\CompanyBundle\Entity\Branch $branch
     */
    public function removeBranch(\ACME\CompanyBundle\Entity\Branch $branch)
    {
        $this->branches->removeElement($branch);
    }

    /**
     * Get branches
     *
     * @return Doctrine\Common\Collections\Collection 
     */
    public function getBranches()
    {
        return $this->branches;
    }

    /**
     * Get branches
     *
     * @return array An array of branches
     */
    public function getBranchesArray()
    {
        return $this->branches->toArray();
    }

    /**
     * Get children
     *
     * @return array An array of children
     */
    public function getChildren()
    {
        return $this->children->toArray();
    }

    /**
     * Set parent
     *
     * @param ACME\CompanyBundle\Entity\User $parent
     * @return User
     */
    public function setParent(\ACME\CompanyBundle\Entity\User $parent = null)
    {
        $this->parent = $parent;
    
        return $this;
    }

    /**
     * Get parent
     *
     * @return ACME\CompanyBundle\Entity\User 
     */
    public function getParent()
    {
        return $this->parent;
    }

    /**
     * Set isActive
     *
     * @param boolean $isActive
     * @return User
     */
    public function setIsActive($isActive)
    {
        $this->isActive = $isActive;
    
        return $this;
    }

    /**
     * Get isActive
     *
     * @return boolean 
     */
    public function getIsActive()
    {
        return $this->isActive;
    }

    /**
     * Set contact
     *
     * @param ACME\CompanyBundle\Entity\Contact $contact
     * @return User
     */
    public function setContact(\ACME\CompanyBundle\Entity\Contact $contact = null)
    {
        $this->contact = $contact;
    
        return $this;
    }

    /**
     * Get contact
     *
     * @return ACME\CompanyBundle\Entity\Contact 
     */
    public function getContact()
    {
        return $this->contact;
    }
    
     /**
     * Erases the user credentials.
     */
    public function eraseCredentials()
    {
 
    }
    
    /**
     * Add userRole
     *
     * @param ACME\CompanyBundle\Entity\Role $userRole
     * @return User
     */
    public function addUserRole(\ACME\CompanyBundle\Entity\Role $userRole)
    {
        $this->userRoles[] = $userRole;
    
        return $this;
    }

    /**
     * Remove userRole
     *
     * @param ACME\CompanyBundle\Entity\Role $userRole
     */
    public function removeUserRole(\ACME\CompanyBundle\Entity\Role $userRole)
    {
        $this->userRoles->removeElement($userRole);
    }
    
    /**
     * Get userRoles
     *
     * @return Doctrine\Common\Collections\Collection 
     */
    public function getUserRoles()
    {
        return $this->userRoles;
    }

    /**
     * Gets an array of roles.
     * 
     * @return array An array of Role objects
     */
    public function getRoles()
    {
        return $this->getUserRoles()->toArray();
    }

    /**
     * Add children
     *
     * @param ACME\CompanyBundle\Entity\User $children
     * @return User
     */
    public function addChildren(\ACME\CompanyBundle\Entity\User $children)
    {
        $this->children[] = $children;
    
        return $this;
    }

    /**
     * Remove children
     *
     * @param ACME\CompanyBundle\Entity\User $children
     */
    public function removeChildren(\ACME\CompanyBundle\Entity\User $children)
    {
        $this->children->removeElement($children);
    }
}