Getting list of all databases with Mongoose

Question

There are some similar questions but all of them involves using the MongoDB NodeJS driver instead of Mongoose ODM.

I read the docs but couldn't find such functionality.

Answer 1

You can't directly get the list from the connection provided by mongoose, but it's easy to do with the mongo Admin object as it contains a function called listDatabases:

var mongoose = require('mongoose')
    , Admin = mongoose.mongo.Admin;

/// create a connection to the DB    
var connection = mongoose.createConnection(
    'mongodb://user:pass@localhost:port/database');
connection.on('open', function() {
    // connection established
    new Admin(connection.db).listDatabases(function(err, result) {
        console.log('listDatabases succeeded');
        // database list stored in result.databases
        var allDatabases = result.databases;    
    });
});

Answer 2

A very modern approach to get list of all mongo databases using mongoose (version 6.10.*) is to Create a mongoose connection to connect to Mongo's admin database and make sure you have an admin user.

Mongoose object is a very complex object. To list the db's :

const connection = `mongodb://${encodeURIComponent(username)}:${encodeURIComponent(password)}@${hostname}:${port}/admin`

mongoose is a very complex object with promises for executing several functions. to list the db's :

mongoose.connect(connection,  {  useNewUrlParser: true ,  useUnifiedTopology: true }).then( (MongooseNode) => { 

/* I use the default nativeConnection object since my connection object uses a single hostname and port. Iterate here if you work with multiple hostnames in the connection object */
                    
const nativeConnetion =  MongooseNode.connections[0]

//now call the list databases function
    new Admin(nativeConnetion.db).listDatabases(function(err, results){
        console.log(results)  //store results and use
    });
})

Result:

{ databases:
   [ { name: 'admin', sizeOnDisk: 184320, empty: false },
     { name: 'config', sizeOnDisk: 73728, empty: false },
     { name: 'local', sizeOnDisk: 73728, empty: false },
     { name: 'test', sizeOnDisk: 405504, empty: false } ],
  totalSize: 737280,
  ok: 1 }