How to views all documents in a particular collection of database in MongoDB through mongo Shell?

Question

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

> 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

Answer 1

OK, let's start from basics!

After you have connected to mongod with command mongo.

• List databases with command show dbs

iot:PRIMARY> 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> use iot

switched to db iot

• List collections on that DB with show collections command

iot:PRIMARY> show collections data header key

• Make query to one of those collections

iot:PRIMARY> 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.<collection_name>.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.

Answer 2

Ref:

https://docs.mongodb.com/manual/tutorial/query-documents/

Select All Documents in a Collection

To select all documents in the collection, pass an empty document as the query filter parameter to the find method. The query filter parameter determines the select criteria:

db.inventory.find( {} )

These operation corresponds to the following SQL statement:

SELECT * FROM inventory

Answer 3

First choose the database: use <database_name>

Show out all collections: show collections OR db.getCollectionNames()

Show all documents: db.<collection_name>.find()

Show all document in easy-to-read and attractive format: db.<collection_name>.find().pretty

Answer 4

show dbs

use your database name in my case, I'm using - use smartbank then - show collections - just to check the document collections name. and finally, db. your collection name.find() or find({}) -

db.users.find() or db.users.find({}) or db.users.find({_id: ObjectId("60c8823cbe9c1c21604f642b")})

you can specify _id:ObjectId(write the document id here) to get the single document