level

import { Level } from 'level'; // Specify types of keys and values for better type safety. // The generic type parameters default to Level<string, string>. // Use { valueEncoding: 'json' } for objects, otherwise 'utf8' is common. const db = new Level<string, any>('./my-database', { valueEncoding: 'json' }); async function runExample() { try { // Ensure the database is open before operations if (db.status === 'closed') { await db.open(); } // Add an entry with key 'user:1' and a JSON object value await db.put('user:1', { name: 'Alice', age: 30 }); console.log('Added user:1'); // Add multiple entries using batch operation await db.batch([ { type: 'put', key: 'user:2', value: { name: 'Bob', age: 24 } }, { type: 'put', key: 'user:3', value: { name: 'Charlie', age: 35 } } ]); console.log('Added user:2 and user:3'); // Get value of key 'user:1' const user1 = await db.get('user:1'); console.log('Value of user:1:', user1); // Iterate entries with keys greater than 'user:1' console.log('Users greater than user:1:'); for await (const [key, value] of db.iterator({ gt: 'user:1' })) { console.log(` Key: ${key}, Value:`, value); } // Example of a sublevel const userEmails = db.sublevel<string, string>('emails', { valueEncoding: 'utf8' }); await userEmails.put('alice', 'alice@example.com'); const aliceEmail = await userEmails.get('alice'); console.log('Alice email:', aliceEmail); } catch (error) { console.error('Database operation failed:', error); } finally { // Always close the database when done if (db.status === 'open') { await db.close(); console.log('Database closed.'); } } } runExample();