Fetching Documents from Mongo Collection using Karras

Question

Let's assume that I have a collection in mongodb, where all of its documents take the following structure.

{
    "_id":5,
    "key-name":"test",
    "meta-data":{
        "user-id":2,
        "status":2
    }
}

Let assume I want to find all collections where "user-id" = 2. I can do this easily Via the mongo shell using following function.

db.mycol.find({"meta-data.user-id" : 2})

I need to retrieve these documents via clojure. Therefore, I have the following set of functions.

Following are my code so far I have.

(ns demo.repository
  (:use karras.core)
  (:use karras.sugar)
  (:use karras.collection))

(def mongo-connection (atom nil))
(def mandate-db (atom nil))

(defn mongo-connect []
  (if (nil? @mongo-connection)
    (do
      (swap! mongo-connection (constantly (connect "192.168.0.6" 27017)))
      (swap! mandate-db (constantly (mongo-db @mongo-connection "mydb"))))))

(defn mongo-close []
  (if-not (nil? @mongo-connect)
    (.close @mongo-connect)))

(defn- job-collection [] (collection @mandate-db "mycol"))

(defn retrieve-doc [id]
  (fetch (job-collection) {"meta-data.user-id" id}))

retrieve-doc is the function I intent to use to fetch documents. The following function does the job.

(fetch (job-collection) {"meta-data.user-id" id})

And this is how you can solve this with Karras

Answer 1

The Answer:

(fetch (job-collection) {"meta-data.user-id" id})

Answer 2

Try this:

(fetch (job-collection) {:meta-data {:user-id id}})