clj-rethinkdb

A RethinkDB client for Clojure. Tested and supported on RethinkDB 2.0.x, it uses the v4 protocol introduced in RethinkDB 2.0, so it won't work on older versions. clj-rethinkdb 0.10.x supports back to RethinkDB 0.13.

Install

Changes

All changes are published in the CHANGELOG. Of particular note, 0.10.x is the last release track supporting Clojure 1.6 and below.

Usage

(require '[rethinkdb.query :as r])

(with-open [conn (r/connect :host "127.0.0.1" :port 28015 :db "test")]
  (r/run (r/db-create "test") conn)

  (-> (r/db "test")
      (r/table-create "authors")
      (r/run conn))
       
  (comment "This is equivalent to the previous query; db on connection is implicitly
  used if no db is provided."
  (-> (r/table-create "authors")
      (r/run conn)))
      
  ;; Create an index on the field "genre".
  (-> (r/db "test")
      (r/table "authors")
      (r/index-create "genre" (r/fn [row]
                                (r/get-field row :genre)))
      (r/run conn))

  (-> (r/db "test")
      (r/table "authors")
      (r/insert [{:name "E.L. James"
                  :genre "crap"
                  :country "UK"
                  :books ["Fifty Shades of Grey"
                          "Fifty Shades Darker"
                          "Fifty Shades Freed"]
                  :tags ["serious" "adult" "spicy"]}
                 {:name "Stephenie Meyer"
                  :genre "crap"
                  :country "USA"
                  :books ["Twilight" "New Moon" "Eclipse" "Breaking Dawn"]
                  :tags ["weird" "serious"]}])
      (r/run conn))

  ;; Use the "genre" index we created to get all books with the genre of "crap".
  (-> (r/db "test")
      (r/table "authors")
      (r/get-all ["crap"] {:index "genre"})
      (r/filter (r/fn [row]
                  (r/eq "Stephenie Meyer" (r/get-field row "name"))))
      (r/run conn))

  (-> (r/db "test")
      (r/table "authors")
      ;; Filter the table (one would normally use an index for that).
      (r/filter (r/fn [author]
                  (r/eq "E.L. James" (r/get-field author :name))))
      ;; Update the books for all authors matching the above filter by appending a new title to the array field :books.
      (r/update (r/fn [author]
                  {:books (-> author (r/get-field :books) (r/append "Fifty More Gray Books"))}))
      (r/run conn))

  ;; Update all authors with a field called :number-of-books that contains the count of things in the :books field.
  (-> (r/db "test")
      (r/table "authors")
      (r/update (r/fn [author]
                  {:number-of-books (-> author (r/get-field :books) (r/count))}))
      (r/run conn))

  ;; Create a compound index on country and genre.
  (-> (r/db "test")
      (r/table "authors")
      (r/index-create "country-genre" (r/fn [row]
                                        [(r/get-field row :country) (r/get-field row :genre)]))
      (r/run conn))

  ;; Use the compound index to access all books of a given genre published by authors from a given country.
  (-> (r/db "test")
      (r/table "authors")
      (r/get-all [["UK" "crap"]] {:index "country-genre"})
      (r/run conn))

  ;; Create a compound multi index to access all authors in a given country with a given tag.
  (-> (r/db "test")
      (r/table "authors")
      (r/index-create "country-tags" (r/fn [row]
                                       (r/map (r/get-field row :tags)
                                              (r/fn [tag]
                                                [(r/get-field row :country) tag])))
                      {:multi true})
      (r/run conn))

  ;; While creating indices, it is often useful to see what actually gets generated for every row:
  (-> (r/db "test")
      (r/table "authors")
      (r/map (r/fn [row]
               (r/map (r/get-field row :tags)
                      (r/fn [tag]
                        [(r/get-field row :country) tag]))))
      (r/run conn))

  ;; Use the country/tags index to access all authors within a country that have the tag.
  (-> (r/db "test")
      (r/table "authors")
      (r/get-all [["USA" "weird"]] {:index "country-tags"})
      (r/run conn)))

See full documentation at http://apa512.github.io/clj-rethinkdb/ (work in progress).