databank-mongodb

databank-mongodb

This is the MongoDB driver for Databank.

License

Copyright 2011-2015 E14N https://e14n.com/

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Usage

To create a MongoDB databank, use the Databank.get() method:

var Databank = require('databank').Databank;

var db = Databank.get('mongodb', {});

The driver takes the following parameters:

• host: the host to connect to. Defaults to localhost.
• port: the port to connect to. Defaults to 27017.
• dbname: the database to use. Defaults to test.
• dbuser: the username. Defaults to null, meaning no authentication.
• dbpass: the password. Defaults to null.
• schema: the database schema, as described in the Databank README.
• checkSchema: whether to synchronize the database with the schema argument at connection time. Defaults to true.
• rs_name: replica set name to use. If this is set, host and port are ignored.
• hosts: array of hosts in the replica set you want to connect to. These can be either arrays of [host, port] or strings (meaning use the default port).

Database structures

Databank "types" map to MongoDB collections.

The "pkey" of a schema will be mapped to the _id value in the database. For example, consider a schema with a single type, like the following:

{"person": {"pkey": "username"}}

An object like the following:

{"username": "evanp", "age": 43}

...would be stored in the database as:

{"_id": "evanp", "age": 43}

The "indices" in a schema will be used to create indices in the database.

Simple types

Arrays and integers are stored in wrapped objects. The following call creates a new array:

var db = Databank.get("mongo", {});

db.connect({}, function(err) {
    db.create("friends", "frodo", ["sam", "merry", "pippin"], function(err, friendsList) {
       // done
    });
});

The stored object in the "friends" collection in MongoDB looks like:

{"_id": "frodo", "_v": ["sam", "merry", "pippin"], "_s": true}

Here, the value is stored in the "_v" field, and the "_s" field stores a flag indicating that we've made a little shim.

Similarly for integer types:

db.incr("age", "evanp", function(err, newAge) { });

The stored object will be:

{"_id": "evanp", "_v": 43, "_s": true}

Atomic changes are made for most of the methods.

TODO

See https://github.com/e14n/databank-mongodb/issues