How to views all documents in a particular collection of database in MongoDB through mongo Shell? In the MongoDB shell, how to views all documents in a particular collection for the current database that I'm using?

when i am trying through the query 

&gt; db.getCollection().find()


To getting the error as mention below 

2017-10-14T00:57:34.363+0530 E QUERY    [thread1] Error: collection constructor called with undefined argument :
DB.prototype.getCollection@src/mongo/shell/db.js:34:16
@(shell):1:1


I am also uploading the screen shot of mongo shell command prompt here
OK, let's start from basics!

After you have connected to mongod with command mongo.


List databases with command show dbs


iot:PRIMARY&gt; show dbs
    admin  0.000GB 
    iot    0.020GB 
    local  0.042GB
    test   0.000GB 
    testi  0.000GB



Select one of the DB's with use iot command


iot:PRIMARY&gt; use iot

switched to db iot


List collections on that DB with show collections command


iot:PRIMARY&gt; show collections
data
header
key



Make query to one of those collections 


iot:PRIMARY&gt; db.header.find()
{ "_id" : "1b5caa", "temp1" : "Temperature", "pressure1" : "Pressure", "humidity1" : "Humidity", "uv1" : "UV", "BusV1" : "Solar Panel (V)", "Current1" : "Solar Panel Current (mA)", "BusV2" : "Battery (V)", "Current2" : "Battery Current (mA)" }
{ "_id" : "30444", "temp1" : "Temperature", "pressure1" : "Pressure", "humidity1" : "Humidity" }
{ "_id" : "239684", "temp1" : "Temperature", "pressure1" : "Pressure", "humidity1" : "Humidity" }


So, you need to be connected WANTED database with use command and you need to show the one collection what you want to query with db.&lt;collection_name&gt;.find()

How to see to what database I'm connected currently? Just give command db and you get the answer what is your current DB.