Reading documents from MongoDB

In the previous recipe, we created a BSON document in MongoDB. Now, in this recipe, we will learn how to read it using the gopkg.in/mgo.v2/bson package, which helps to query the MongoDB collection.

How to do it…

1. Install the gopkg.in/mgo.v2, gopkg.in/mgo.v2/bson, and github.com/gorilla/mux packages, using the go get command, as follows:

$ go get gopkg.in/mgo.v2
$ go get gopkg.in/mgo.v2/bson
$ go get github.com/gorilla/mux

2. Create read-record-mongodb.go. Then we connect to the MongoDB database, read all the documents from an employee collection, marshal the list to JSON, and write it to an HTTP response stream, as follows:

package main
import 
(
  "encoding/json"
  "log"
  "net/http"
  "github.com/gorilla/mux"
  mgo "gopkg.in/mgo.v2"
  "gopkg.in/mgo.v2/bson"
)
const 
(
  CONN_HOST = "localhost"
  CONN_PORT = "8080"
  MONGO_DB_URL = "127.0.0.1"
)
var session *mgo.Session
var connectionError error
func init() 
{
  session, connectionError = mgo.Dial(MONGO_DB_URL)
  if...