Clojurians Log v2

I keep seeing { :aliases { :db/cardinality :db.cardinality/many } } as a schema in examples. what does it do?

I also see transactions with negative :db/id. why is that?

also, I know that a lot of the core library operates on an atom “connection”. are these changes executed synchronously?

I want to pretty much ignore the atom and use my own state container

OK, so it sounds like the alias is being defined as an attribute which is cardinality many. got it.

it also sounds like negative db/id’s are used as temporary IDs?

That is precisely the case. You can use negative IDs within your transaction to establish relationships, DataScript will fill-in the correct ones.

I have another newbie question. I’m playing around with moving parts of my application to DataScript

my first attempt is at routing. here’s my initial transaction:

[{:db/id -1
           :router/current :tap-list
           :router/routes [{:id :tap-list
                            :label "Taps"}
                           {:id :inspector
                            :label "Inspector"}]}]

this is kind of weird, though, because routing is a kind of singleton thing. I’m not sure how to write the transaction to update this yet

thinking about this now: perhaps it would be better to model it as a cardinality-many of history, and query for the latest one

gotta figure out how to preserver order..

I usually model singletons with idents. Idents are implemented via a separate attribute with the {:db/unique :db.unique/identity} property. Nowadays, this comes built-in (https://github.com/tonsky/datascript/blob/master/src/datascript/db.cljc#L24). In your example, you could the replace {:db/id -1} with {:db/ident :router} and use that throughout your app.