Using Laravel Eloquent to Return Data recursively from a table indexing into 2 tables - itself and another table

Make your comment model a morphable like the example in the documentation: https://laravel.com/docs/5.7/eloquent-relationships#one-to-many-polymorphic-relations

This way you can do something like:

$post = Post::with('comments.comments.comments')->find(3);
dd($post->toArray());

And it will have all comments on this post, all comments on those comments, and all comments on those comments (3 levels deep with 4 queries, 1 for the post and 3 for all nested comments)

@lostdreamer_nl thank you, I didn't know about morphTo and morphMany, this is definitely a step in the right direction.

Does this return up to 3 levels of comments to post with ID=1? Is there an eloquent way to retrieve an unlimited tree of comments?

$post = Post::with('comments.comments.comments')->find(1);

Doing

        $post = Post::with('comments.comments.comments.comments.comments.comments.comments.comments')->find(1);

doesnt make much sense.

Also, each of my posts and comments can have one or more 'likes' (it is similar to 'comments' in that it is also polymorphic).

How can I retrieve a post with:

1. Unlimited nesting of comments
2. For each level of comments, retrieve the likes to that comment from the likes table.
3. likes to the post from the likes table

This doesn't quite work, I don't get the likes data back:

New attempt (your method, using commentable_id and commentable_type):

        $post = Post::with('comments.comments.comments')->with('likes')->find(1);

Older attempt (using a different method, neither of them work):

        // Note: if you dont also return author_id here, the author object returned below will be null
        $returnedCommentTree = $returnedCommentTree
            ->select('id', 'comment_hash', 'comment_on_type', 'comment_on_post_id', 'comment_on_comment_id', 'user_id', 'body', 'created_at')
            ->with([
                // Note: MUST also return the author_id field above
                'user' => function ($query) {
                    $query->where('deleted_at', NULL)
                        ->select('id', 'name');
                },

                'childrenComments' => function ($query) {
                    $query->where([
                        ['is_removed', '=', '0'],
                        ['deleted_at', '=', NULL],
                    ])
                        ->select('id', 'comment_hash', 'comment_on_type', 'comment_on_post_id', 'comment_on_comment_id', 'user_id', 'body', 'created_at')
                        ->with([
                            // Note: MUST also return the author_id field above
                            'user' => function ($query) {
                                $query->where('deleted_at', NULL)
                                    ->select('id', 'name');
                            },
                            'likes'
                        ]);
                },

                'likes'
            ]);

ok, now you are going into 'infinite nesting'.

Basically there are 2 ways:

• using parent_id on the children (parent child)
• using left / right on the parent (Nested set model )

(Google for "nested set model" to get more info on it)

They both have their pros and cons, the most important ones are:

• parent child is fast with inserting new data, but slow with getting all the data back
• Nested set is the other way around: adding children or moving them will get slower with more data, but getting all nested data is very fast.

It's up to you to decide which version is the best for your project (how many views vs how many data is being added)

There is ofcourse also the way of only getting the first layer of comments including the count of their comments and their likes. Now you can show the first comments, and a 'show replies' button underneath them. Clicking that button would trigger an ajax call to get the comments of this comment (and their comment count + likes),