Getting the id of an inserted entity in datomic?

Question

After I run a transaction in datomic to insert a value, how I can use the return value of the transaction to get the ids of any entities that were created?

Here is a sam

Answer 1

The Tupelo Datomic library has a function (td/eids tx-result) to easily extract the EIDs created in a transaction. For example:

  ; Create Honey Rider and add her to the :people partition
  (let [tx-result   @(td/transact *conn* 
                        (td/new-entity :people ; <- partition is first arg (optional) to td/new-entity 
                          { :person/name "Honey Rider" :location "Caribbean" :weapon/type #{:weapon/knife} } ))
        [honey-eid]  (td/eids tx-result)  ; retrieve Honey Rider's EID from the seq (destructuring)
  ]