https://github.com/viesti/puihin

Trying out Datomic
https://github.com/viesti/puihin

Last synced: about 2 months ago
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Trying out Datomic

• Host: GitHub
• URL: https://github.com/viesti/puihin
• Owner: viesti
• License: epl-1.0
• Created: 2015-01-18T19:29:34.000Z (almost 10 years ago)
• Default Branch: master
• Last Pushed: 2015-01-25T21:08:25.000Z (almost 10 years ago)
• Last Synced: 2023-03-23T02:06:24.682Z (almost 2 years ago)
• Language: Clojure
• Size: 141 KB
• Stars: 1
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# puihin

## Demo of Datomic as document like storage:

Let's have a tree/document -like structure with nodes having text

attribute and child nodes (imagine a table of contents).

```clojure

(def schema

  [{:db/id #db/id[:db.part/db]

    :db/ident :node/text

    :db/valueType :db.type/string

    :db/cardinality :db.cardinality/one

    :db/fulltext true

    :db/index true

    :db.install/_attribute :db.part/db}

   {:db/id #db/id[:db.part/db]

    :db/ident :node/children

    :db/valueType :db.type/ref

    :db/cardinality :db.cardinality/many

    :db/isComponent true

    :db.install/_attribute :db.part/db}])

```

Datomic allows to write a whole 'document' at once with [nested maps](http://docs.datomic.com/transactions.html#sec-3-4):

```clojure

(defn document-like-tree-data [root]

  [{:db/id root

    :node/text "root"

    :node/children

    [{:node/text "middle"

      :node/children

      [{:node/text "leaf1"}

       {:node/text "leaf2"}]}]}])

```

[Pull API](http://blog.datomic.com/2014/10/datomic-pull.html) allows

to get it back as a nested map.

```clojure

(d/pull (d/db conn) '[*] root-entity-id)

{:db/id 17592186045418,

 :node/text "root",

 :node/children

 [{:db/id 17592186045419,

   :node/text "middle",

   :node/children

   [{:db/id 17592186045420, :node/text "leaf1"}

    {:db/id 17592186045421, :node/text "leaf2"}]}]}

```

Neat!

## License

Copyright © 2015 Kimmo Koskinen

Distributed under the Eclipse Public License either version 1.0 or (at

your option) any later version.