Any advice on how to structure data for an elementary school report card? There are numeric metrics Several lists and text fields… but I’m hoping to keep them flexible; So the data might be:

[{:db/id 3
     :components [[:metrics "Metrics" ["Productivity"
                                       "Leadership"
                                       "Happiness"]]
                  [:ol "Achievements" ["Won the spelling bee."]]
                  [:ol "Weaknesses"]
                  [:ol "Coach goals"]
                  [:ol "Player goals"]
                  [:textarea "Coach comments"]
                  [:textarea "Player comments"]]}])

Alternatively maybe I should be making a new entity for ‘metrics’ and ‘achievements’ etc

If I'm reading your intentions here correctly, I think there's a mismatch between what you're attempting in the code snippet, and what datomic does -

in particular, datomic doesn't natively support vectors or lists

is the entity in your code snippet a student?

yup

okay, when you say "the categories might change", what part of the snippet are you referring to?

new/different metrics for example “Math"

and new categories

like a list of friends or something I haven’t thought of

still not sure what a category is… is "Achievements" a category?

yes, though I don’t have any special meaning to ‘category’

heh, alright. well, at a first blush, here's how I'd do it -

a student entity would have these (optional) attributes: :metrics, :achievements, :weaknesses, :goals, and :comments

:metrics, :achievements, and :weaknesses look like they can just be db.type/string with :db.cardinality/many

is there a way to preserve order in a many relationship? or would I need to make them entities that relate to each other to do that?

ordering isn't really straightforward - the easiest way to do it, imo, is to give the things you want to order an :order attribute and sort in your client code

so if you need to order those first three, you'd need to make them entities, rather than just strings

ah nice

:goals and :comments would be entities in their own right, because you need to note authors

they'd just have an attribute for the goal or comment, and then another attribute to note the author - either an enum-like thing if you just want it to be :coach or :player, or you could represent people as their own entities and refer to them from there

gotcha

thanks that makes a lot of sense

okay, good

is there a shorthand way to insert my root with it’s various sub-entities, or should I write a transformation from my datastructure that produces all the entities and throw them at transact?

you can nest your entities when you transact them… let me get you a link

Can't link you directly to the content, but search for "nested" here: http://docs.datomic.com/transactions.html

also, note that even though the syntax for nesting uses vectors, the entities don't end up being ordered in datomic

ooo great!

thank you very much

sure, have fun!

@bhagany: cool, I didn’t know about that. every once in a while you need to re-read the datomic docs for added features

@stijn: heck yeah, I learn new things every time

hi nice people one question: if I do a transaction using upsert, but nothing is changing (let's say I'm transacting data with the same value that is already on the DB), this will create a new transaction anyway or it's going to skip since nothing was going to change?

@wilkerlucio: that will create a new transaction

thanks @arohner, so I think I'm better do a query to check if the data is the same to avoid unintended history I think

@wilkerlucio: depends on what you’re trying to do. Re-asserting a fact can be a valid strategy as well. “on today’s date, I observed X to still be true"

@arohner: my case is just a simple facebook login, I'm actually login at the client-side, I just send the access token and then I create/read the user ID, is on that point that I was going to always transact (in case it didn't generate a new one), but since it does I'll just check if the user is there and avoid when it is. makes sense?

sure

I’d like to debug a query that is slow in production. Is there a way to clear the peer cache, without restarting?

arohner: not that I know of. I'd bet you can, but it'll involve reflection and poking around in the internals of a db (which may violate a thing you signed when you downloaded datomic)