Clojurians Log v2

Is there a way to query for entities that don't have a certain attribute? Something like "show me all entities that have a :company/id but don't have a :company/owner"

Check out missing? in the query docs

@zilti you can also do

[?e .....]
(not [?e :attr])

Looks like that datomic-peer do not respect socks proxy JVM props -DsocksProxyHost=127.0.0.1 -DsocksProxyPort=5000 Is it a know issue? slurp respect this settings both for dns resolution and packages. Datomic do not respect the proxy for names resolution I can't know about packages

Hi, I want to restore my backup db then I run bin/transctor the transactor

datomic-pro-0.9.5561 bin/transactor config/dev-transactor-template.properties
Launching with Java options -server -Xms1g -Xmx1g -XX:+UseG1GC -XX:MaxGCPauseMillis=50
Starting datomic:<dev://localhost:4334/&lt;DB-NAME>&gt;, storing data in: data ...
System started datomic:<dev://localhost:4334/&lt;DB-NAME>&gt;, storing data in: data

datomic-pro-0.9.5561 bin/datomic restore-db backup.tgz datomic:<dev://localhost:4334/hummingbirg-dev>                                                                                        
java.lang.IllegalArgumentException: :storage/invalid-uri Unsupported protocol:
        at datomic.error$arg.invokeStatic(error.clj:57)
        at datomic.error$arg.invoke(error.clj:52)
        at datomic.error$arg.invokeStatic(error.clj:55)
        at datomic.error$arg.invoke(error.clj:52)
        at datomic.backup$fn__19707.invokeStatic(backup.clj:306)
        at datomic.backup$fn__19707.invoke(backup.clj:304)
        at clojure.lang.MultiFn.invoke(MultiFn.java:233)

your backup (source) needs to be an unzipped backup, not a tar

I got the same error when I unzipped

untarred/unzipped

it should be a directory

a top level dir with roots and values dirs inside of it

backup ls
owner  roots  values

ah

you need to make a URI for it

sorry

it will be like: file:///User/Home/backup/

https://docs.datomic.com/on-prem/backup.html#uri-syntax

it worked

thanks !

no problem

Okay, I don't get it... or-join works completely different from what I expect. When there's no result fulfilling any of the clauses in or-join it will match everything. Is that on purpose? How can I avoid that?

I thought this:

(d/q '[:find ?eid .
       :in $ ?comp-domain ?comp-name
       :where
       (or-join [?eid]
                [?eid :company/name ?comp-name]
                [?eid :company/domain ?comp-domain])]
     db comp-domain (:company/name data)))

(or (d/q '[:find ?eid .
       :in $ ?comp-domain ?comp-name
       :where
       [?eid :company/domain ?comp-domain]]
     db comp-domain))
     (d/q '[:find ?eid .
       :in $ ?comp-domain ?comp-name
       :where
       [?eid :company/name ?comp-name]]
     db (:company/name data))))

In the first query, you are getting all ?eid s because the or-join you specify does not unify with ?comp-name nor ?comp-domain. So, practically, the ?comp-domain/`?comp-name` in your :in clause are not the same as the ones you use in the or branches of your or-join

So your first query now says “Give me al entity ids of entities that have either a name, or a domain”, the bindings in your :in make no difference

If you change (or-join [?eid] ...) to (or-join [?eid ?comp-domain ?comp-name] ...), do you get what you want?

I'm trying...

Yes, that gives me an empty result, which is correct in this case

And it works for a valid binding too. Thanks! I misinterpreted how that first vector works in or-join, I thought that is to declare the common variable.

Q: what’s the best way to query for the most recently created entity (with other conditions) in Datalog?

It declares what variables from outside the or-join to unify with ^^

I can include a :where [?e :some/attr _ ?t] and then sort all results by ?t but it feels like there must be some way to use max to do this

🙂

Here are some interesting time rules: https://github.com/Datomic/day-of-datomic/blob/master/tutorial/time-rules.clj maybe that helps ^^

perfect! thank you 🙂

Not sure if your use is exactly in there, but I often use it as a reference if I want to find something history related 🙂

it’s a good start. I’ll be able to make it work from this

haha, teach a man to fish, and all 🙂

exactly. you supplied the bait