Mongo-dart - MongoDB driver for Dart programming language

Server-side driver library for MongoDb implemented in pure Dart.

Basic usage

Obtaining connection

  var db = Db("mongodb://localhost:27017/mongo_dart-blog");
  await db.open();

  var db = await Db.create("mongodb+srv://<user>:<password>@<host>:<port>/<database-name>?<parameters>");
  await db.open();

Querying

Method find returns stream of maps and accept query parameters, usually build by fluent API query builder provided by mongo_dart_query as top level getter where

  var coll = db.collection('user');
  await coll.find(where.lt("age", 18)).toList();
  
  //....
  
  await coll
      .find(where.gt("my_field", 995).sortBy('my_field'))
      .forEach((v) => print(v));

  //....
  
  await coll.find(where.sortBy('itemId').skip(300).limit(25)).toList();

Method findOne take the same parameter and returns Future of just one map (mongo document)

  val = await coll.findOne(where.eq("my_field", 17).fields(['str_field','my_field']));

Take notice in these samples that unlike mongo shell such parameters as projection (fields), limit and skip are passed as part of regular query through query builder

Inserting documents

  await usersCollection.insertAll([
    {'login': 'jdoe', 'name': 'John Doe', 'email': 'john@doe.com'},
    {'login': 'lsmith', 'name': 'Lucy Smith', 'email': 'lucy@smith.com'}
  ]);

Updating documents

You can update whole document with method save

  var v1 = await coll.findOne({"name": "c"});
  v1["value"] = 31;
  await coll.save(v1);

or you can perform field level updates with method update and top level getter modify for ModifierBuilder fluent API

  coll.update(where.eq('name', 'Daniel Robinson'), modify.set('age', 31));

Removing documents

  students.remove(where.id(id));
  /// or, to remove all documents from collection
  students.remove();

Simple app on base of JSON ZIPS dataset

import 'package:mongo_dart/mongo_dart.dart';

void main() async {
  void displayZip(Map zip) {
    print(
        'state: ${zip["state"]}, city: ${zip["city"]}, zip: ${zip["id"]}, population: ${zip["pop"]}');
  }
  var db =
      Db("mongodb://reader:vHm459fU@ds037468.mongolab.com:37468/samlple");
  var zips = db.collection('zip');
  await db.open();
  print('''
******************** Zips for state NY, with population between 14000 and 16000,
******************** reverse ordered by population''');
  await zips
      .find(where
          .eq('state', 'NY')
          .inRange('pop', 14000, 16000)
          .sortBy('pop', descending: true))
      .forEach(displayZip);
  print('\n******************** Find ZIP for code 78829 (BATESVILLE)');
  var batesville = await zips.findOne(where.eq('id', '78829'));
  displayZip(batesville);
  print('******************** Find 10 ZIP closest to BATESVILLE');
  await zips
      .find(where.near('loc', batesville["loc"]).limit(10))
      .forEach(displayZip);
  print('closing db');
  await db.close();
}

Building aggregation queries

import 'package: mongo_dart/mongo_dart.dart';

main() async {
  final db = Db('mongodb://127.0.0.1/testdb');
  final pipeline = AggregationPipelineBuilder()
    .addStage(
      Match(where.eq('status', 'A').map['\$query']))
    .addStage(
      Group(
        id: Field('cust_id'),
        fields: {
          'total': Sum(Field('amount'))
        }
      )).build();
  final result =
    await DbCollection(db, 'orders')
      .aggregateToStream(pipeline).toList();
  result.forEach(print);
}

Secure connection

You can connect using a secured tls/ssl connection in one of this two ways:

setting the secure connection parameter to true in db.open()

    await db.open(secure: true);

adding a query parameter => "tls=true" (or "ssl=true").

    var db = DB('mongodb://www.example.com:27017/test?tls=true&authSource=admin');
              or
    var db = DB('mongodb://www.example.com:27017/test?ssl=true&authSource=admin');

When you use the mongodb+srv url schema, the "tls" (or "ssl") parameter is implicitly considered true.

No certificates can be used.

Atlas (MongoDb cloud service) connection

Atlas requires a tls connection, so now it is possible to connect to this cloud service. When creating a cluster Atlas shows you three ways of connecting: Mongo shell, Driver and MongoDb Compass Application. The connection string is in Seedlist Connection Format (starts with mongodb+srv://).

Take the Url related to the Driver mode and pass it to Db.create().

Please, not that Db.create is an asynchronous constructor, so you have to await for it.

  var db = await Db.create("mongodb+srv://<user>:<password>@<host>:<port>/<database>?<parameters>");
  await db.open();

jodinathan/mongo_dart