CODEWITHSUNDEEP
swiftdatabaseparse-platformrelational-databaserelationship
Stefan DeClerck
Stefan DeClerck

Reputation: 1192

How would one structure a mutual relationship between two users in Parse?

I am playing around with my own Parse server and would like to build a social media app just for fun. Just learning how to structure it and get everything developed.

One of the problems that I am having trouble wrapping my head around is how I would create a relationship structure between two users where the connection is mutual.

You would have to, on both ends, accept the relationship request.

I would also like to know how I would query for the friends list. Which would how would I query for the people the user has mutual connections with?

I hear that a friendship table relationship would be helpful for structuring a relationship with friends. But I would like to make it a mandatory mutual connection for people to be friends.

Upvotes: 0

Views: 144

Answers (2)

philipxy
philipxy

Reputation: 15118

All you actually need is Request(person, friend) "PERSON asked to friend FRIEND", because requited and unrequited friendships can be extracted by query. You might prefer to keep those two relationships separately instead: Requited(person, friend) "PERSON asked to friend FRIEND and FRIEND asked to friend PERSON" & Unrequited(person, friend) "PERSON asked to friend FRIEND and FRIEND hasn't asked to friend PERSON". If a row (p, f) is in Requited then so is (f, p), and neither is in Unrequited. The two tables UNION to Request. But then you need to move rows between the tables when people friend or unfriend others. What is "best" logically depends on patterns of update & querying, and there will be likely be another "best" when implementation is included.

Database design is the identification of sufficient relationships/associations to describe any application situation. Each gets a table whose rows make a true statement from some characterizing statement template, aka predicate. Each query returns the rows that satisfy its own relationship/association, characterized by a predicate built from base predicates. Normalization helps with relationship/association/predicate/table choice, and so do information modeling methods. Pick a method (eg Object-Role Modeling) and learn it & how & why it leads to "good" designs while avoiding "bad" ones.

Upvotes: 1

Aaron Bannin
Aaron Bannin

Reputation: 127

Create a new Object call "Relationships" and store both PFUser id's.

Upvotes: 0

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