lum_lokijs

const Loki = require('lokijs'); const LokiIndexedAdapter = require('lokijs/src/loki-indexed-adapter'); async function initializeDatabase() { const adapter = new LokiIndexedAdapter('my-loki-app'); const db = new Loki('my-database.db', { adapter: adapter, autosave: true, autosaveInterval: 4000 // Save every 4 seconds }); // Load the database from persistence, or create if it doesn't exist await new Promise((resolve, reject) => { db.loadDatabase({}, (err) => { if (err) { console.error('Error loading database:', err); reject(err); } else { console.log('Database loaded or created.'); resolve(); } }); }); let users = db.getCollection('users'); if (!users) { users = db.addCollection('users', { unique: ['email'], autoupdate: true }); console.log('"users" collection created.'); } // Insert some data if the collection is empty if (users.count() === 0) { users.insert({ name: 'Alice', email: 'alice@example.com', age: 30 }); users.insert({ name: 'Bob', email: 'bob@example.com', age: 24 }); users.insert({ name: 'Charlie', email: 'charlie@example.com', age: 35 }); console.log('Initial data inserted.'); } // Find and update a document let bob = users.findOne({ name: 'Bob' }); if (bob) { bob.age = 25; users.update(bob); // Explicit update might be needed for certain changes like array mutations console.log('Bob updated:', users.findOne({ name: 'Bob' })); } // Query data const youngUsers = users.find({ age: { '$lt': 30 } }); console.log('Users under 30:', youngUsers); // Save changes explicitly (autosave also does this) await new Promise((resolve, reject) => { db.saveDatabase((err) => { if (err) reject(err); else resolve(); }); }); console.log('Database saved.'); return db; } initializeDatabase().catch(console.error);