tnederlof
User Friendship Schema Design
I have been thinking of the most efficent way to setup a schema to take Users and associate them with one another when they “friend” each other. I found a thread from 2017 with some good ideas (Best-practise question - follow and friends posts in ecto - #6 by kokolegorille), however there was some pretty intense queries that have to be done on the Friendship table (to check both directions). Is there a more efficient (from a querying perspective)? Right now I have a User and a Friendship schema where in Friendship there is a “friend_a_id” and a “friend_b_id”.
Any thoughts would be greatly appreciated!
First Post!
stefanchrobot
Two options come to mind:
- Store the friendship in sorted order, i.e.
friend_a_id<friend_b_id. On the boundary of the context, always make sure to sort the ids before querying. - Store the relationship twice. When unfriending, make sure to delete both entries.
0
Popular in Questions
I believe there are people here who are dealing with CSV files import on the daily basis, and since Excel is a really popular tool there ...
New
What is the idiomatic way of matching for not nil in Elixir?
E.g.,
First way:
defp halt_if_not_signed_in(conn, signed_in_account) when...
New
Hi,
I am new to Elixir. I am trying to use the DateTime component to insert a date into MySQL however the there seems to be no way to fo...
New
After calling mix ecto.create I get this error:
17:00:32.162 [error] GenServer #PID<0.412.0> terminating
** (Postgrex.Error) FATAL...
New
I am trying to figure out how Mix knows whether the environment is test, dev, or prod – where is this set?
Thanks.
New
I have a relationship of love and hate with Elixir. Lots of things are just absolutely right, but there are some things that are kind of ...
New
I am trying to implement my new.html.eex file to create new posts on my website.
new.html.eex:
<h1>Create Post</h1>
<%= ...
New
Hello again - after a longish gap I’ve decided I really must dig into Elixir and see what’s been happening here - so I have a few questio...
New
Hi,
I need to transform a list of numbers into a map where the keys are the indexes and the values are the original values of the list. ...
New
Lets say I have map like this fetching from my database
%{"_id" => #BSON.ObjectId<58eb1a7a9ad169198c3dXXXX>, "email" => ...
New
Other popular topics
We have an ECS cluster with 4 services, where each task joins a single cluster, via discovery ECS discovery service.
Currently when I de...
New
As promised, the first release candidate of Phoenix 1.3.0 is out! This release focuses on code generators with improved project structure...
New
After calling mix ecto.create I get this error:
17:00:32.162 [error] GenServer #PID<0.412.0> terminating
** (Postgrex.Error) FATAL...
New
Hi all,
I’ve just started learning Elixir and Phoenix Framework, so please pardon my n00bness at this stage.
I’m trying to use Postgres...
New
I asked this very same question on twitter and got some interesting feedback, but I thought it would be a good question to ask here as we...
New
Using vs code and installed ElixirLS: support and debugger.
And I got an error popped up on start up says
Failed to run ‘elixir’ comma...
New
Hey,
Just curious what are the main benefits of Elixir compared to Clojure?
When is Elixir more useful than Clojure and vice versa?
Th...
New
Hi,
I need to transform a list of numbers into a map where the keys are the indexes and the values are the original values of the list. ...
New
Hello!
Sorry for this astonishing simple question, but I’m really stuck. I try to set up the intellij-elixir plugin, but I don’t know ho...
New
I wrote this comment on r/haskell, and it’s not popular there. :wink: But I think I’m on to something…
Haskell reminds me of Java, and e...
New
Categories:
Sub Categories:
Forums
Popular Tags
- #ecto
- #liveview
- #troubleshooting
- #learning-elixir
- #deployment
- #library
- #erlang
- #testing
- #genserver
- #mix
- #absinthe
- #remote-other
- #otp
- #plug
- #how-to-question
- #macros
- #postgres
- #channels
- #elixirconf
- #exunit
- #discussion
- #code-sync
- #javascript
- #podcasts
- #onsite
- #dialyzer
- #docker
- #authentication
- #umbrella
- #full-time-contract
- #podcasts-by-brainlid
- #ecto-query
- #elixir-ls
- #phoenix_html
- #iex
- #blog-post
- #graphql
- #genstage
- #ai
- #websockets
- #supervisor
- #advent-of-code
- #elixirconf-us
- #distillery
- #processes
- #forms
- #api
- #metaprogramming
- #security
- #performance









