Rage DB

Rage is a very simple but incredibly useful data store for prototyping or working with in memory datasets.

Data is manipulated in memory as basic Clojure map but can be flushed to disk as plain JSON at any point.

Pros

• Very easy to use (just a library)
• Useful for prototyping
• Great for memory datasets where you need small ish JSON dumps

Cons

• Memory
• Slow
• Flat files

Quickstart

Clojars

[rage-db "1.0"]

Maven

<dependency>
  <groupId>rage-db</groupId>
  <artifactId>rage-db</artifactId>
  <version>0.1.0-SNAPSHOT</version>
</dependency>

Usage

Create a new database

(ns foo
  (require [rage-db.core :as rdb]))

;; Create a new in memory database
(def db (rdb/create "demo"))

;; #<Atom@7079cda4: #rage_db.core.RDB{:db-name "demo", :store {}}>

;; Insert some data

(rdb/insert db :users
  {:first "owain"
   :last  "lewis"
   :email "owain@owainlewis.com"})

;; Now let's query for a user

(rdb/where db :users :email "owain@owainlewis.com")

;; [{:email "owain@owainlewis.com", :first "owain", :last "lewis"}]

;; Once we are done we can flush our data to disk

(rdb/dump db)

;; "data/users-1408216769512"

Querying the database

Use the keyspace function to return all records for a keyspace.

;; Let's insert some data
(insert mem-db :users {:first "Owain" :last "Lewis"})
(insert mem-db :users {:first "Jack" :last "Dorsey"})

;; Return all users

(def all-users (rdb/keyspace mem-db :users))

You can use the ? function to find data. By default the underlying store in Rage is a simple Clojure map.

;; Find a user in the users keyspace with a given email

(rdb/? db :users (fn [row] (= (:email row) "jack@twitter.com")))

Easy query

Two methods are provided to make querying easier. where and drop-where

;; Select any rows where the first name is equal to "jack"
(rdb/where mem-db :users :first "jack")

;; Drop any rows where the first name is jack
(rdb/drop-where db :users :first "jack")

JSON queries

To return your result set as json simply call the as-json function like this

(rdb/as-json
  (rdb/where mem-db :users :first "jack"))

Save your data

Data can be flushed to disk as JSON like this

(rdb/dump db)

This command returns a file path to your database. Notice how the files are saved with a timestamp representing the database creation time. All data is stored as pretty printed json.

{
  "users" : [ {
    "email" : "owain@owainlewis.com",
    "first" : "owain",
    "last" : "lewis"
  }, {
    "email" : "jack@twitter.com",
    "first" : "jack",
    "last" : "dorsey"
  }, {
    "email" : "bill@microsoft.com",
    "first" : "bill",
    "last" : "gates"
  } ]
}

Loading data

Loading data is equally easy

(def db (rdb/load-db "users-1408216769512"))

License

Copyright © 2014 Owain Lewis

Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.