Doctrine send an entity to DQL's NEW construct

问题:

I have a Blog application in Symfony2 with Doctrine, made of three entities

• Post
• Comment

• User

• one Post can have many Comments

• one User can have many comments

this application has an json API call "/me/comments"

I would like it to return

[
    {
       'text': 'great post',
       ... 10 other field a comment can have ...
       'post': { 'id': 3}
    },
    {
       'text': 'i dont like it',
       ... 10 other field a comment can have ...
       'post': {'id': 4}
    },

]

The normal doctrine function returns me all the relation (User, Post) in the json, which I don't want as Post can contains huge text, so i'm only interested in the Id

I've tried many solutions and I've found that one

http://docs.doctrine-project.org/en/latest/reference/dql-doctrine-query-language.html#new-operator-syntax

so now my DQL query looks like that

SELECT NEW CommentDTO(c) FROM Comment as c WHERE c.author = :user

the constructor of CommentDTO looks like that

__construct(Comment c) {
   $this->text = c.getText();
   $this->post = [ 'id' => c.getPost().getId() ];
}

when I execute it I got

{
   "code":500,
   "message":"Argument 1 passed to MVMS\\ApiBundle\\Entity\\CommentDTO::__construct() must be an instance of MVMS\\ApiBundle\\En
tity\\Comment, integer given"

}

of course I could give the parameter one by one but Comment has a dozen of fields and sending them one by one seems highly hackish.

Is there a way to send the object directly ?

回答1:

As mentioned by @Cerad in the comments, there is no current way to achieve this, according to the documentation, which is still relevant in 2017:

Note that you can only pass scalar expressions to the constructor.

I could not find a related feature request in the issue tracker, so it will likely not be implemented in the foreseeable future.