Parse - Using relations versus pointers?

Question

I am using Parse as my backend. I have problems setting up the correct relation between objects.

I basically have a class named Post, each post belongs to a user(PFU

Answer 1

In your usecase, a pointer is preferable over a PFRelation. You can include the user info by adding includeKey in your query:

[query includeKey:@"user"];

A way to get a comment count on your post is to add every new comment to an array of pointers in your Post.

It is easy to get stuck in the old SQLish ways when you start using NoSQL databases. If a counter is desirable, you could add a cloud code afterSave function on the comment object that updates the "comments" column of the Post class by adding a pointer to the saved comment to the "comments" array in Post. This way, when you fetch a post you can also use

[query includeKey:@"comments"];

which will give you the Post AND all the comments in one query. If you only need the count, you ommit the includeKey, but you still have an array in "comments" with the pointers, so the comment count is the length of the array.