Question

I have an Entity “BlogPosts” with yml mapping:

type: entity
table: blog_posts
id:
  id:
    type: integer
    generator: { strategy: AUTO }
fields:
  body:
    type: text
  created_at:
    type: datetime
manyToMany:
  replies:
    targetEntity: BlogPosts
    inversedBy: replyTo
    orderBy: {"id": "DESC"}
    orphanRemoval: true
    joinTable:
      name: blog_post_replies
      joinColumns:
        reply_to_id:
          referencedColumnName: id
      inverseJoinColumns:
        reply_id:
          referencedColumnName: id
  replyTo:
    targetEntity: BlogPosts
    mappedBy: replies
manyToOne:
  user:
    targetEntity: User
    inversedBy: posts
    joinColumns:
      user_id:
        referencedColumnName: id
        nullable: false

The problem is, when i try to fetch the data using a JOIN, the result is empty.

    $query = $em->createQuery("SELECT p, rl FROM <Bundle>:BlogPosts p JOIN p.replies rl WHERE p.user = 1");
    $posts = $query->getResult(); // Returns empty array

But it works perfectly without a join:

    $query = $em->createQuery("SELECT p FROM <Bundle>:BlogPosts p WHERE p.user = 1");
    $posts = $query->getResult(); // Works as intended

What am i missing? I am really desperate 🙁

EDIT:
Just found out, that it returns only posts, that have replies. How can i select all posts and if it has replies, replies too?

Answer 1

So i found the problem! Instead of JOIN i used LEFT JOIN:

$query = $em->createQuery("SELECT p, rl FROM <Bundle>:BlogPosts p LEFT JOIN p.replies rl WHERE p.user = 1");
$posts = $query->getResult(); // Now it works like a charm!

So now MySQL joins the result to the blog posts! When using a simple JOIN, it tries to join the posts to the replies, in witch case the result will be empty if the post doesn’t have any!