mniam v4.1.0

mniam

Yet another mongodb native driver facade. Takes care of:

• mongo URI parsing
• opening and closing DB connections
• opening collections

Install by running

npm install mniam

API

database(url, [options])

Connect to database mniam-test and create friends collection with index on name field.

const db = database('mongodb://localhost/mniam-test');
const friends = db.collection({
  name: 'friends',
  indexes: [[{ name: 1 }]]
});

Mniam is using MongoClient to establish the connection: full mongo database URLs are supported. The database function also takes a hash of options divided into db/server/replset/mongos allowing you to tweak options not directly supported by the unified url string format.

const db = database('mongodb://localhost/mniam-test', {
  db: {
    w: -1
  },
  server: {
    ssl: true
  }
});

collection.save

Add a new documents:

const item = await friends.save({
  name: 'Alice',
  age: 14,
};
console.log('Item id:', item._id);

collection.findOneAndUpdate

Update a document:

const item = await friends.findAndModify({ _id: item._id }, {
  $set: { age: 15 }
});
console.log('Alice is now:', item.age);

collection.deleteOne

Remove a document:

await friends.deleteOne({ name: 'Alice' });

Iteration

Use query, fields and options to create and configure cursor. Iterate over the results of the query using toArray, eachSeries, eachLimit methods.

• items - can be used as async iterator

for await (const friend of friends.query({ age: { $gt: 21 } }).items()) {
  console.log('My friend over 21 years old', friend.name);
}

• toArray - converts query results into array

const arr = await friends.query({ age: { $gt: 21 } }).toArray();
console.log('My friends over 21 years old', arr);

• eachSeries - calls onItem sequentially for all results

await friends
  .query()
  .fields({ name: 1 })
  .eachSeries(async item => console.log('Name:', item.name));
console.log('All friends listed.');

• eachLimit - iterates over all results calling onItem in parallel, but no more than limit at a time

await friends
  .query()
  .options({ sort: { age: 1 } })
  .eachLimit(4, async item => console.log('Friend', item));
console.log('All friends listed.');

Aggregation

Mniam collections provides flex API for aggregation pipeline:

const results = await friends
  .aggregate()      // start pipeline
  .project({ author: 1, tags: 1 })
  .unwind('$tags')
  .group({
    _id : { tags : '$tags' },
    authors : { $addToSet : '$author' },
    count: { $sum: 1 }
  })
  .sort({ count: -1 })
  .toArray();
console.log(results);

In addition to toArray you can use eachSeries and eachLimit to iterate over aggregation results. Each aggregation stage ($project, $unwind, $sort, etc.) has a corresponding function with the same name (without $). You can also pass a traditional array of stages to .pipeline(stages) method, and set options with .options({}) method.

License

MIT