How to get all collections from all databases in MongoDB

In this article, we will see how to get all collections from all databases in in MongoDB Server. We can get all databases and the collections in them by using db.getMongo() and db.getDBNames() methods with forEach method.

1. Run the following command from mongo shell.

db.getMongo().getDBNames().forEach(
        function(v, i){
            print(
                v + '\n\t' +
                db.getSiblingDB(v).getCollectionNames().join('\n\t'))}
            ) 

2. Run the following query from the Linux shell.

mongo --eval "
    db.getMongo().getDBNames().forEach(
        function(v, i){
            print(
                v + '\n\t' +
                db.getSiblingDB(v).getCollectionNames().join('\n\t'))}
            )" 

3. Both will give same output:

admin
        system.keys
        system.users
        system.version
config
        system.sessions
        transactions
example
        test
examples
        test
flights
        flightData
local
        oplog.rs
        replset.election
        replset.minvalid
        replset.oplogTruncateAfterPoint
        startup_log
        system.replset
        system.rollback.id
m201
        people
        products
        students
        supplies
money
        employees
myDb
        analytics
        books
        hello
        stores
        tab
        technology
        test1
        testData
        users
r2schools
        addressBook
        employees
        inventory
        records
        student
        survey
test
        test