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refset 2022-01-31T17:17:21.453669Z
XT doesn't support wildcard attribute vars, which is needed for a single not to be sufficient, so you'd either need a not per attribute (e.g. generating verbose queries), or you can define orphan? as a custom function that executes an inner query per attribute: https://gist.github.com/refset/25d8ae03c69993831c9c23cf7e12a537
👍 1
quoll 2022-02-01T11:06:42.147839Z
I’ve never needed to before! (Outside of unit tests)
😄 1
quoll 2022-01-31T18:13:16.629679Z
This is where it gets tricky between databases.
For instance, Asami has several options, but for this query it could just use:
:find ?e :where [?e] (not [_ _ ?e])
💯 2
refset 2022-01-31T21:22:59.870529Z
oh cool, I don't think I've seen anyone reduce a triple clause to merely [?e] before 🙂
denik 2022-01-31T02:08:02.449029Z
what’s the best way to find entities without db.type/ref relationships? in a graph these could be called orphan nodes.
quoll 2022-01-31T05:06:42.280129Z
Thinking of Datomic:
:find ?e :where [?e ?a ?v] [?a :db/ident] (not [?o ?r ?e] [?r :db/ident])
The :db/ident statements are because unbound patterns make Datomic nervous. (I’m not sure if it's needed in the not expression)