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mongo-dart/mongo_dart

151

mongo-dart / mongo_dart

Dart

Mongo_dart: MongoDB driver for Dart programming language


READ ME

Mongo-dart - MongoDB driver for Dart programming language.

Pub Build Status

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

Basic usage

Obtaining connection

  Db db = new Db("mongodb://localhost:27017/mongo_dart-blog");
  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] (http://media.mongodb.org/zips.json)

import 'package:mongo_dart/mongo_dart.dart';

main() async {
  void displayZip(Map zip) {
    print(
        'state: ${zip["state"]}, city: ${zip["city"]}, zip: ${zip["id"]}, population: ${zip["pop"]}');
  }
  Db db =
      new 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();
}

See also