NeDB - PublicVar/electron-wiki GitHub Wiki
NeDB
Store user data on the user computer.
Install
npm install --save-dev @types/nedb
Note SystemJS:
You need to tell SystemJS where to find nedb. To do that, add the following line to the map object in systemjs.config.js (this assumes you specified an 'npm' path in the 'paths' object):
'nedb': 'npm:nedb/browser-version/out/nedb.min.js'
Note Angular2:
To use the Datastore into Angular2 you need to import it:
import * as Datastore from 'nedb';
API
Documentation. The next sections are samples of code for different actions. For more explanations about how it works and why, I strongly recommend you to click on the learn more link.
Creating/loading a database
var Datastore = require('nedb')
, db = new Datastore({ filename: 'path/to/datafile', autoload: true });
Insert documents
Insert a simple document:
var doc = { hello: 'world'
, n: 5
, today: new Date()
, nedbIsAwesome: true
, notthere: null
, notToBeSaved: undefined // Will not be saved
, fruits: [ 'apple', 'orange', 'pear' ]
, infos: { name: 'nedb' }
};
db.insert(doc, function (err, newDoc) { // Callback is optional
// newDoc is the newly inserted document, including its _id
// newDoc has no key called notToBeSaved since its value was undefined
});
Insert several documents:
db.insert([{ a: 5 }, { a: 42 }], function (err, newDocs) {
// Two documents were inserted in the database
// newDocs is an array with these documents, augmented with their _id
});
Finding documents
// Let's say our datastore contains the following collection
// { _id: 'id1', planet: 'Mars', system: 'solar', inhabited: false, satellites: ['Phobos', 'Deimos'] }
// { _id: 'id2', planet: 'Earth', system: 'solar', inhabited: true, humans: { genders: 2, eyes: true } }
// { _id: 'id3', planet: 'Jupiter', system: 'solar', inhabited: false }
// { _id: 'id4', planet: 'Omicron Persei 8', system: 'futurama', inhabited: true, humans: { genders: 7 } }
// { _id: 'id5', completeData: { planets: [ { name: 'Earth', number: 3 }, { name: 'Mars', number: 2 }, { name: 'Pluton', number: 9 } ] } }
// Finding all planets in the solar system
db.find({ system: 'solar' }, function (err, docs) {
// docs is an array containing documents Mars, Earth, Jupiter
// If no document is found, docs is equal to []
});
Counting documents
// Count all planets in the solar system
db.count({ system: 'solar' }, function (err, count) {
// count equals to 3
});
// Count all documents in the datastore
db.count({}, function (err, count) {
// count equals to 4
});
Updating documents
// Let's use the same example collection as in the "finding document" part
// { _id: 'id1', planet: 'Mars', system: 'solar', inhabited: false }
// { _id: 'id2', planet: 'Earth', system: 'solar', inhabited: true }
// { _id: 'id3', planet: 'Jupiter', system: 'solar', inhabited: false }
// { _id: 'id4', planet: 'Omicron Persia 8', system: 'futurama', inhabited: true }
// Replace a document by another
db.update({ planet: 'Jupiter' }, { planet: 'Pluton'}, {}, function (err, numReplaced) {
// numReplaced = 1
// The doc #3 has been replaced by { _id: 'id3', planet: 'Pluton' }
// Note that the _id is kept unchanged, and the document has been replaced
// (the 'system' and inhabited fields are not here anymore)
});
Removing documents
// Let's use the same example collection as in the "finding document" part
// { _id: 'id1', planet: 'Mars', system: 'solar', inhabited: false }
// { _id: 'id2', planet: 'Earth', system: 'solar', inhabited: true }
// { _id: 'id3', planet: 'Jupiter', system: 'solar', inhabited: false }
// { _id: 'id4', planet: 'Omicron Persia 8', system: 'futurama', inhabited: true }
// Remove one document from the collection
// options set to {} since the default for multi is false
db.remove({ _id: 'id2' }, {}, function (err, numRemoved) {
// numRemoved = 1
});