在Doctrine中获取部分选择的映射字段

Question

I have a post entity which may represent the Post or Comment to another post.

/**
 * @ORM\ManyToOne(targetEntity="Post", inversedBy="comments")
 */
private $post;
public function setPost($post) { $this->post = $post; return $this; }
public function getPost() { return $this->post; }

/**
 * @ORM\OneToMany(targetEntity="Post", mappedBy="post", cascade={"remove"})
 */
private $comments;
public function getComments() { return $this->comments; }
....

So normally i can get parent Post by ->getPost();.

Now i want to optimize request and using partial select like this one

$query = $this->getEntityManager()
->createQuery(
    "SELECT partial post.{id, title, Post}
    FROM XXXMyBundle:Post post
    ORDER BY post.id ASC
    ")

But each time i see errors like

There is no mapped field named 'Post' on class

I tried to change field name in query to post_id, post or postId but it didn't help.

Is there any way to get the post_id (that's name of the field in database) ?

Answer 1

OK, thanks to this question i solved my problem.

"SELECT partial post.{id, title}, partial p.{id}
             FROM XXXMyBundle:Post post
             LEFT JOIN post.post p
             ORDER BY post.id ASC