How to inherit entity from model in symfony?

Question

symfony

Good afternoon everyone. There was a problem extending entity from model.
There is an entity

<?php

namespace GCS\AdminBundle\Entity;

use Doctrine\ORM\Mapping as ORM;
use \GCS\BillingBundle\Model\BillingAccount;
/**
 * Account
 *
 * @ORM\Table(name="gcs_account")
 * @ORM\Entity
 */
class Account extends BillingAccount
{
    /**
     * @var integer
     *
     * @ORM\Column(name="id", type="integer", nullable=false)
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="IDENTITY")
     */
    private $id;
    
    /**
     * ORM\Column(name="fos_user_id", type="integer", unique=true)
     */
    //protected $fos_user_id;	
  
    /**
     * @ORM\OneToOne(targetEntity="\GCS\KernelBundle\Entity\User")
     * @ORM\JoinColumn(name="fos_user_id", referencedColumnName="id")
     **/
    private $fos_user_id;			

    /**
     * @var string
     *
     * @ORM\Column(name="username", type="string", length=255, nullable=false)
     */
    private $username;

    /**
     * @var string
     *
     * @ORM\Column(name="pwd", type="string", length=255, nullable=false)
     */
    private $pwd;

    /**
     * @var string
     *
     * @ORM\Column(name="email", type="string", length=255, nullable=false)
     */
    private $email;

    /**
     * @var string
     *
     * @ORM\Column(name="description", type="string", length=255, nullable=false)
     */
    private $description;

    /**
     * @var string
     *
     * @ORM\Column(name="is_active", type="boolean", options={"default"= 1})
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    private $isActive;

    /**
     * @var boolean
     *
     * @ORM\Column(name="deleted", type="boolean", options={"default"=0})
     */
    private $deleted = 0;

    /**
     * @ORM\OneToMany(targetEntity="\GCS\AdminBundle\Entity\Hotel", mappedBy="account")
     */
    protected $hotels;

    /**
     * @ORM\ManyToOne(targetEntity="\GCS\AdminBundle\Entity\Language")
     * @ORM\JoinColumn(name="language_id", referencedColumnName="id",  nullable=true)
     */    
    private $defaultLanguage;
    

    /**
     * Constructor
     */
    public function __construct()
    {
    	parent::__construct();
        $this->hotels = new \Doctrine\Common\Collections\ArrayCollection();
    }

I inherit it from Model\BillingAccount, the model code is below

<?php

namespace GCS\BillingBundle\Model;

use Doctrine\ORM\Mapping as ORM;

/**
 * Balance
 *
 * @ORM\Table(name="billing_account")
 * @ORM\MappedSuperclass
 */
 
class BillingAccount
{
  public function __construct()
    {
        $this->balance = 0;
    }

      		
    /**
     * @ORM\Column(name="balance", type="integer",  nullable=false)
     */
    protected $balance = 0;
        

    /**
     * Set balance
     *
     * @param integer $balance
     * @return Account
     */
    public function setBalance($balance)
    {
        $this->balance = $balance;

        return $this;
    }

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

The problem is that with extends from model I get an entity with additional fields from the model, but I lose the ORM description of the fields specified in the model.
The output is an entity with parent fields, but without an ORM annotation, and these fields are missing in the database.
Outcome:

<?php

namespace GCS\AdminBundle\Entity;

use Doctrine\ORM\Mapping as ORM;
use \GCS\BillingBundle\Model\BillingAccount;
/**
 * Account
 *
 * @ORM\Table(name="gcs_account")
 * @ORM\Entity
 */
class Account extends BillingAccount
{
    /**
     * @var integer
     *
     * @ORM\Column(name="id", type="integer", nullable=false)
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="IDENTITY")
     */
    private $id;
    
    /**
     * ORM\Column(name="fos_user_id", type="integer", unique=true)
     */
    //protected $fos_user_id;	
  
    /**
     * @ORM\OneToOne(targetEntity="\GCS\KernelBundle\Entity\User")
     * @ORM\JoinColumn(name="fos_user_id", referencedColumnName="id")
     **/
    private $fos_user_id;			

    /**
     * @var string
     *
     * @ORM\Column(name="username", type="string", length=255, nullable=false)
     */
    private $username;

    /**
     * @var string
     *
     * @ORM\Column(name="pwd", type="string", length=255, nullable=false)
     */
    private $pwd;

    /**
     * @var string
     *
     * @ORM\Column(name="email", type="string", length=255, nullable=false)
     */
    private $email;

    /**
     * @var string
     *
     * @ORM\Column(name="description", type="string", length=255, nullable=false)
     */
    private $description;

    /**
     * @var string
     *
     * @ORM\Column(name="is_active", type="boolean", options={"default"= 1})
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    private $isActive;

    /**
     * @var boolean
     *
     * @ORM\Column(name="deleted", type="boolean", options={"default"=0})
     */
    private $deleted = 0;

    /**
     * @ORM\OneToMany(targetEntity="\GCS\AdminBundle\Entity\Hotel", mappedBy="account")
     */
    protected $hotels;

    /**
     * @ORM\ManyToOne(targetEntity="\GCS\AdminBundle\Entity\Language")
     * @ORM\JoinColumn(name="language_id", referencedColumnName="id",  nullable=true)
     */    
    private $defaultLanguage;
    

    /**
     * Constructor
     */
    public function __construct()
    {
    	parent::__construct();
        $this->hotels = new \Doctrine\Common\Collections\ArrayCollection();
    }

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

    /**
     * Set fosUserId
     *
     * @param integer $fos_user_id
     * @return Account
     */
    public function setFosUserId($fos_user_id)
    {
        $this->fos_user_id = $fos_user_id;

        return $this;
    }

    /**
     * Get fosUserId
     *
     * @return integer 
     */
    public function getFosUserId()
    {
        return $this->fos_user_id;
    }

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

        return $this;
    }

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

    /**
     * Set pwd
     *
     * @param string $pwd
     * @return Account
     */
    public function setPwd($pwd)
    {
        $this->pwd = $pwd;

        return $this;
    }

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

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

        return $this;
    }

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

    /**
     * Set description
     *
     * @param string $description
     * @return Account
     */
    public function setDescription($description)
    {
        $this->description = $description;

        return $this;
    }

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

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

        return $this;
    }

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

    /**
     * Set deleted
     *
     * @param boolean $deleted
     * @return Account
     */
    public function setDeleted($deleted)
    {
        $this->deleted = $deleted;

        return $this;
    }

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

    /**
     * Add hotels
     *
     * @param \GCS\AdminBundle\Entity\Hotel $hotels
     * @return Account
     */
    public function addHotel(\GCS\AdminBundle\Entity\Hotel $hotels)
    {
        $this->hotels[] = $hotels;

        return $this;
    }

    /**
     * Remove hotels
     *
     * @param \GCS\AdminBundle\Entity\Hotel $hotels
     */
    public function removeHotel(\GCS\AdminBundle\Entity\Hotel $hotels)
    {
        $this->hotels->removeElement($hotels);
    }

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

    /**
     * Set defaultLanguage
     *
     * @param \GCS\AdminBundle\Entity\Language $defaultLanguage
     * @return Account
     */
    public function setDefaultLanguage(\GCS\AdminBundle\Entity\Language $defaultLanguage = null)
    {
        $this->defaultLanguage = $defaultLanguage;

        return $this;
    }

    /**
     * Get defaultLanguage
     *
     * @return \GCS\AdminBundle\Entity\Language 
     */
    public function getDefaultLanguage()
    {
        return $this->defaultLanguage;
    }
<b>    /**
     * @var integer
     */
    protected $balance;</b>


    /**
     * Set balance
     *
     * @param integer $balance
     * @return Account
     */
    public function setBalance($balance)
    {
        $this->balance = $balance;

        return $this;
    }

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

Answer 1

Off documentation
Read more carefully. Dostrina has several inheritance options, and you mixed Mapped Superclass with something of your own .... MappedSuperclass cannot be an entity, and should not have its own table

Answer 2

Look towards Custom Repositories.