教义2中的ManyToOne关系

Question

I am trying to get into Doctrine 2 with Zend Framework 2. I have 2 Database Tables:

advertable

• id
• advert_title
• advert_user_id

user table

• id
• username

I now have a form to add a new advert and want to inject the advert_user_id, when I save the advert in my table. I have created 2 Entities:

/** Advert
 * 
 * @ORM\Table(name="advert")
 * @ORM\Entity(repositoryClass="Advert\Repository\AdvertRepository")
 */  
class Advert
{
/**
 * @var integer
 *
 * @ORM\Column(name="id", type="integer", nullable=false)
 * @ORM\Id
 * @ORM\GeneratedValue(strategy="IDENTITY")
 */
private $id;

/**
 * @var integer
 *
 * @ORM\Column(name="advert_user_id", type="integer", nullable=false)
 */
private $advertUserID;

/** 
 * @ORM\ManyToOne(targetEntity="User", inversedBy="adverts") 
 * @ORM\JoinColumn(name="advert_user_id", referencedColumnName="id")
 */ 
protected $user;


/**
 * Set advertUserID
 *
 * @param integer $advertUserID
 * @return Advert
 */

 public function setAdvertUserID($advertUserID)
{
    $this->advertUserID = (int) $advertUserID;

    return $this;
}

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

/** 
 * Set user 
 * 
 * @param \Advert\Entity\User $user 
 * @return Advert 
 */ 
public function setUser(\Advert\Entity\User $user = null) 
{ 
    $this->user = $user; 

    return $this; 
} 

/** 
 * Get user 
 * 
 * @return \Advert\Entity\User 
 */ 
public function getUser() 
{ 
    return $this->user; 
}

And the following User Entity

/**
 * User
 *
 * @ORM\Table(name="user")
 * @ORM\Entity
 */
 class User
 {
/**
 * @var integer
 *
 * @ORM\Column(name="id", type="integer", nullable=false)
 * @ORM\Id
 * @ORM\GeneratedValue(strategy="IDENTITY")
 */
private $id;

 /**
 * @ORM\OneToMany(targetEntity="Advert", mappedBy="user")
 */
private $adverts;

In my controller I now try to do the following:

if ($form->isValid()) 
{
  $advert->setAdvertUserID('13');  //Static for testing     
  $this->getEntityManager()->persist($advert));
  $this->getEntityManager()->flush();

Unfortunately the entry in the database is always null. If I delete the @ORM\\ManyToOne $user in my Advert Entity it works. The setup does allow me to read out the Username through the Advert Entity, so why can I not save the User ID in my advert table?

Answer 1

First, I would recommend not to name tables and columns explicitely (unless you have a good reason). Also you usually don't need to specify JoinColumn s. Let Doctrine handle those things, it will make life much easier.

Next, your entities should both have getters and setters for each column or relation. Also, the User entity should have a constructor which initializes the $adverts field to a ArrayCollection object. (Doctrine has a CLI command for entity method generation; don't know how it's integrated with ZF, in SF2 it's doctrine:generate:entities )

Now, for the actual problem: The reason why you can't access the user from the advert object is because you have never set that relation. In your setter, you must either pass an entity or a reference to that entity (google for $EM->getReference(…) ). Only then will Doctrine be able to autoload the related entity.

If you only store the ID of the related object, you would have to fetch the entity manually each time because Doctrine doesn't even know of the relation between the entities.

Answer 2

I understand you have the user_id stored in your session and you want to save the user with the advert without first getting the whole user entity from the database. That sounds like a good idea and one query less to execute.

The way to do this is like this:

First clean up your advert entity from the unnecessary and not according to Doctrine2 specs $advertUserID related stuff :)

/** Advert
 * 
 * @ORM\Table(name="advert")
 * @ORM\Entity(repositoryClass="Advert\Repository\AdvertRepository")
 */  
class Advert
{
    /**
     * @var integer
     *
     * @ORM\Column(name="id", type="integer", nullable=false)
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="IDENTITY")
     */
    private $id;

    /** 
     * @ORM\ManyToOne(targetEntity="User", inversedBy="adverts") 
     * @ORM\JoinColumn(name="advert_user_id", referencedColumnName="id")
     */ 
    protected $user;

    /** 
     * Set user 
     * 
     * @param \Advert\Entity\User $user 
     * @return Advert 
     */ 
    public function setUser(\Advert\Entity\User $user = null) 
    { 
        $this->user = $user; 

        return $this; 
    } 

    /** 
     * Get user 
     * 
     * @return \Advert\Entity\User 
     */ 
    public function getUser() 
    { 
        return $this->user; 
    }
}

Then add user by reference to your advert:

$user_id = 13
$entityManager = $this->getEntityManager();

// get User by reference (no queries executed)
$user = $entityManager->getReference('Advert\Entity\User' , $user_id);

// set the User in the Advert using the setUser method
$advert->setUser($user); 

// Persist and flush!
$entityManager->persist($advert));
$entityManager->flush();

Now you can find a user_id in the advert table and no additional queries were executed to do this. Read more on reference proxies here in the Doctrine2 documentation .