fern-flower-lab/sqlg-clj

The SQL Graph with Tinkerpop3 and Clojure

The SQL Graph in Clojure

Utilizes Tinkerpop3 graph over SQL database using sqlg.

Warning

Origin’s library uses J17 for releases (at least for 3.0.x versions), so independently on this Clojure library build you will be forced to use that version too.

Supported DBs

1. PostgreSQL

2. MySQL

3. MariaDB

4. HSQLDB

5. H2

6. MSSQL

Caution

The low-level driver is well tested only with PostgreSQL + C3P0. You are warned.

Config

Basic config is represented by sample.properties

sample.graph.db.type = postgresql
sample.graph.db.host = localhost
sample.graph.db.port = 5432
sample.graph.db.name = sample
sample.graph.db.user = username
sample.graph.db.pass = password

In order to get it prepared use

user=> (require '[sqlg-clj.config :as c])
user=> (def config (-> "sample" c/load-config :sample :graph :db c/db-config))

Same result may be done using EDN config, i.e. directly from your app:

user=> (def config (c/db-config {:port 5432 :pass "password" :user "username" :type "postgresql" :host "localhost" :name "sample"}))

When the config is ready it may be easily read back

user=>(c/config->clj config)
{"jdbc.url" "jdbc:postgresql://localhost:5432/sample", "jdbc.username" "username", "jdbc.password" "password"}

Starting

Open SqlgGraph directly

(def G (c/graph config))

or indirectly

(def G (c/open-graph config))

The last method opens a new TinkerGraph with default configuration or open a new Graph instance with the specified configuration. The configuration may be a path to a file or a Map of configuration options. When gets prepared BaseConfiguration or Configuration object as an argument - returns SqlgGraph.

Using

user=> (require '[sqlg-clj.core :refer :all])
user=> (-> ^Graph G traversal V (has-label "label"))
#object[org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.DefaultGraphTraversal 0x3fffba3f "[GraphStep(vertex,[]), HasStep([~label.eq(label)])]"]

Transactions

In order to store or to unroll the changes were made by some iteration between calls, use

user=> (require '[sqlg-clj.util :as u])
user=> (u/commit! G)
;; or
user=> (u/rollback! G)

respectively.

Examples

create, find, process

user=> (require '[sqlg-clj.util :as u])
user=> (require '[sqlg-clj.data :as d])
user=> (require '[sqlg-clj.core :refer :all])

user=> (-> G (d/add-V :test {:aa 11 :bb 22}))
#object[org.umlg.sqlg.structure.SqlgVertex 0x2e5e87e9 "v[public.test:::14]"]
user=> (-> G (d/add-V :test {:aa 33 :cc 44}))
#object[org.umlg.sqlg.structure.SqlgVertex 0x6ec0ead1 "v[public.test:::15]"]
user=> (u/commit! G)
nil

user=> (def vxs (-> G traversal V (has-label :test) (has :aa) u/into-vec!))
#'user/vxs

user=> (map #(value % :aa) vxs)
(11 33)
user=> (map #(value % :bb) vxs)
(22 nil)
user=> (map #(value % :cc) vxs)
(nil 44)

More info

Please, read original documentation here and here

License

©2022-2023 Fern Flower Lab

Distributed under the MIT License.