I have an User entity. And those users can be friends together. So I defined a self referencing manyToMany unidirectional association (because there is always reciprocity is friendship, right ?).

a piece of my user entity in YML

```
manyToMany:
    friendList:
    targetEntity: User
    joinTable:
      name: user_friend
      joinColumns:
        user_id:
          referencedColumnName: id
      inverseJoinColumns:
        friend_id:
          referencedColumnName: id
    cascade: [persist]

```

When I call `$user->addFriendList($friend)`, and after a persist and a flush, I have `PDOException`:

> 
> SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '1-2' for fey 'PRIMARY'
> 
> 
> 

When I check in the logs, I can see that doctrine is trying to exectue the same insert query twice. 

For your information, my `addFriendList` function

```
public function addFriendList(User $friend)
{
    if (!$this->friendList->contains($friend)) {
        $this->friendList[] = $friend;
        $friend->addFriendList($this);
    }
}

```

Where am I wrong here ?