Relational query with .limit() and descending order does not work as expected.

[vundev]

Issue Description

I have two parse classes User and Post. The user class has relation named posts containing Post objects. When i do
the following query

user.relation("posts", className: Post.className) .query(Post()) .limit(5) .order(.descending("createdAt"))

i got less than 5 objects nevertheless the user has more than 5 posts.

Steps to reproduce

1. Creates 6 posts, let say post 1, post 2, ..., post 6. Post[i] is created before Post[i+1].
2. Delete the last created post (post 6).
3. Then run the provided query with limit 5.

Actual Outcome

The query returns post 5, post 4, post 3 and post 2 (total of 4 posts).

Expected Outcome

My expectation is that the query will omit the deleted object and return the first 5 available objects - post 5 up to post 1.
This happens because the join table representing the relation keeps the id of the deleted object. The limit operator gives 5 object ids including the id of the deleted object. I consider this a bug.

Server

• Parse Server version: 4.10.4
• Operating system: macOS
• Local or remote host (AWS, Azure, Google Cloud, Heroku, Digital Ocean, etc): Local/Heroku

Database

• System (MongoDB or Postgres): MongoDB
• Database version: 8.0.4
• Local or remote host (MongoDB Atlas, mLab, AWS, Azure, Google Cloud, etc): MongoDB Atlas

Client

• SDK (iOS, Android, JavaScript, PHP, Unity, etc): iOS
• SDK version: 3.1.0

[parse-github-assistant]

Thanks for opening this issue!

[vundev]

One workaround i can think of is:
Post.query().where(matchesKeyInQuery(key: "objectId", queryKey: "objectId", query: user.relation("posts", className: Post.className) .query(Post()))) .limit(5) .order(.descending("createdAt"))