incanter.mongodb — incanter/incanter-mongodb 1.9.3

A simple library that provides functions for persisting Incanter data structures using MongoDB.

Use incanter.mongodb in combination with the somnium.congomongo library. For usage examples, see the Congomongo README at http://github.com/somnium/congomongo, and the examples/blog/mongodb_datasets.clj file in the Incanter distribution.

Here are Somnium's descriptions of Congomongo's functions:

(mongo! & args) : Creates a Mongo object and sets the default database. Keyword arguments include: :host -> defaults to localhost :port -> defaults to 27017 :db -> defaults to nil (you'll have to set it anyway, might as well do it now.)

(get-coll coll) : Returns a DBCollection object

(fetch coll & options) : Fetches objects from a collection. Optional arguments include :where -> takes a query map :only -> takes an array of keys to retrieve :as -> what to return, defaults to :clojure, can also be :json or :mongo :from -> argument type, same options as above :one? -> defaults to false, use fetch-one as a shortcut :count? -> defaults to false, use fetch-count as a shortcut

(fetch-one coll & options) : same as (fetch collection :one? true)

(fetch-count coll & options) : same as (fetch collection :count? true)

(insert! coll obj & options) : Inserts a map into collection. Will not overwrite existing maps. Takes optional from and to keyword arguments. To insert as a side-effect only specify :to as nil.

(mass-insert! coll objs & options) : Inserts a sequence of maps.

(update! coll old new & options) : Alters/inserts a map in a collection. Overwrites existing objects. The shortcut forms need a map with valid :_id and :_ns fields or a collection and a map with a valid :_id field.

(destroy! coll query-map) : Removes map from collection. Takes a collection name and a query map

(add-index! coll fields & options) : Adds an index on the collection for the specified fields if it does not exist. Options include: :unique -> defaults to false :force -> defaults to true

(drop-index! coll fields) : Drops an index on the collection for the specified fields

(drop-all-indexes! coll) : Drops all indexes from a collection

(get-indexes coll & options) : Get index information on collection

(drop-database title) : drops a database from the mongo server

(set-database title) : atomically alters the current database

(databases) : List databases on the mongo server

(collections) : Returns the set of collections stored in the current database

(drop-collection coll) : Permanently deletes a collection. Use with care.

fetch-dataset clj

(fetch-dataset & args)

Queries a MongoDB database, accepting the same arguments as somnium.congomongo/fetch, but returning an Incanter dataset instead of a sequence of maps.

Examples:

(use '(incanter core datasets mongodb)) (require '[clojure.core.matrix.dataset :as ds]) (use 'somnium.congomongo)

;; first load some sample data (def data (get-dataset :airline-passengers)) (view data)

;; a MongoDB server must be running on the localhost on the default port ;; for the following steps.

(mongo! :db "mydb") (mass-insert! :airline-data (ds/row-maps data))

;; and then retrieve it ;; notice that the retrieved data set has two additional columns, :_id :_ns (view (fetch-dataset :airline-data))

insert-dataset clj

(insert-dataset mongodb-coll dataset)

Inserts the rows of the Incanter dataset into the given MongoDB collection.

Examples:

(use '(incanter core datasets mongodb)) (require '[somnium.congomongo :refer [mongo! mass-insert!]])

(def data (get-dataset :airline-passengers)) (view data)

;; a MongoDB server must be running on the localhost on the default port ;; for the following steps.

(mongo! :db "mydb") (insert-dataset :airline-data data)

;; notice that the retrieved data set has two additional columns, :_id :_ns (view (fetch-dataset :airline-data))