@jdkealy absolutely yes it can

has anyone ever written a (db) function that takes the nested map form of an entity in transaction and also generates :db/retract's (based on e.g. 'nil' values for fields or missing values in a many relationship)?

or how are you all dealing with this when arbitrarily nested data structures need to be updated?

Hi

@stijn Datomic sure likes flat data/facts 🙂 Usually ended up with something non-generic and/or tried to flatten my data as much as i can

I have a growing number of orders in the DB. I would like to expose an API which would return these orders between dates, as given in a parameter. The simplest thing to do would be to make a query and then iterate over the returned entities. But what is the best way to implement pagination of results?

@michaelr use the :avet index on :order/date and return a 'next-page' token to the client based on either the date, or if you want a fixed set of results the date + the entity id

@augustl yes, but I was looking for something generic because i'm fed up implementing the non-generic 🙂

@stijn Thanks! Will check the docs on how to query an index

@michaelr you can do that with d/datoms

@stijn Checking.. thanks

@stijn No way to specify (> some-date) for the value? Should I be iterating over the whole index?

(d/datoms db :avet (d/entid db :order/date) from-date) will give you all entities as of from-date

Wow interesting

Thanks

@stijn that will give you entities with exactly from-date only

But @michaelr see d/index-range

@favila Thanks. Will check it now

@favila This one works! 🙂

oh yes 🙂