hello, all! i am learning datomic as am unsure how to work with :db.cardinality/many relationships when adding new entities to the collection. e.g.: i have a rule entity that can have multiple :rule/executions (a ref type). from time to time i have to add a new execution to the list. what is the appropriate way of doing it?

is anyone aware of a library that can convert a raw datum to its symbolic/transaction form given a dbval? bonus for resolving its :db/id to a any unique-identity attributes on the corresponding entity

example @spieden?

what is a "symbolic/transaction form"?

sure something like: #datum [1010101 2323232 454545 626262 true] -> [[:some/unique-identity "human-readable-id"] :some/rel-attr [:some/other-unique-identity "also-human-readable"] 626262 true]

basically find idents for the e/a/v numeric ids

there's not going to be a universal way to do that

for the unique-identity attrs you mean?

yes

sure, there can be ambiguity there

for the A it's just (d/ident db-after a)

ok yeah

but attrs don't necessarily need to be named

i see

this is just for debugging the result of applying a transaction

i generate big ones and let datomic prune the redundant stuff for me

.. and am in a situation where i need to see the “diff” that was applied in a human readable form so i can understand what’s going on

gotcha

If there's an attr you have in mind you can try to resolve it specifically

anyway short answer is no, I'm aware of no lib

I think because it's hard to come up with a universal solution, and it's not very hard to roll your own

ok i might make a best effort general one

there are enough different kinds of entities floating around

.. and the relations are a big part of it

in my mind I am imagining mapping some-fn over E A V

and making a list of fns that take db and eid and return either nil or some other representation

bottom out with the eid itself (or maybe even the tempid)

(map (fn [[e a v tx op] ((some-fn unique-attr1 unique-attr2 d/ident #(do %2)) db-after e)) ,,,))

yeah that makes sense

one for each EAV of course

this reminds me, is something like this possible in datomic?

'{:find  [?e ?es ?v]
  :in    [$ [?es ...]]
  :where [[?e ?es ?v]]}

yep

better to use the datoms API for that

just because of result size

i was thinking you could query out the ids of all the unique-attrs and pass them there as ?es

oh yeah, i would constrain in more

you can feed the entire result in, implement the some-fn thing with rules

oh i see

you'll get duplicates if they match multiple ways

sure yeah

but, you can include an index per datom too, then group-by the result

so, it's like seeing all possibilites at once

yeah that would be fine for just making something legible

cool thanks for the advice guys

I am about to import ~2m file entities into datomic that are all a component of different companies. Is it best practice to partition by "company" or by "file"?

Or is there another option I hadn't considered