* `sourceDb` {DatabaseSync} The database to backup. The source database must be open.

* `destination` {string} The path where the backup will be created. If the file already exists, the contents will be

overwritten.

* `options` {Object} Optional configuration for the backup. The

following properties are supported:

* `source` {string} Name of the source database. This can be `'main'` (the default primary database) or any other

database that have been added with [`ATTACH DATABASE`][] **Default:** `'main'`.

* `target` {string} Name of the target database. This can be `'main'` (the default primary database) or any other

database that have been added with [`ATTACH DATABASE`][] **Default:** `'main'`.

* `rate` {number} Number of pages to be transmitted in each batch of the backup. **Default:** `100`.

* `progress` {Function} Callback function that will be called with the number of pages copied and the total number of

pages.

* Returns: {Promise} A promise that resolves when the backup is completed and rejects if an error occurs.

This method makes a database backup. This method abstracts the [`sqlite3_backup_init()`][], [`sqlite3_backup_step()`][]

and [`sqlite3_backup_finish()`][] functions.

The backed-up database can be used normally during the backup process. Mutations coming from the same connection - same

{DatabaseSync} - object will be reflected in the backup right away. However, mutations from other connections will cause

the backup process to restart.

const { backup, DatabaseSync } = require('node:sqlite');

(async () => {

const sourceDb = new DatabaseSync('source.db');

const totalPagesTransferred = await backup(sourceDb, 'backup.db', {

rate: 1, // Copy one page at a time.

progress: ({ totalPages, remainingPages }) => {

console.log('Backup in progress', { totalPages, remainingPages });

},

});

console.log('Backup completed', totalPagesTransferred);

})();

import { backup, DatabaseSync } from 'node:sqlite';

const sourceDb = new DatabaseSync('source.db');

const totalPagesTransferred = await backup(sourceDb, 'backup.db', {

rate: 1, // Copy one page at a time.

progress: ({ totalPages, remainingPages }) => {

console.log('Backup in progress', { totalPages, remainingPages });

},

});

console.log('Backup completed', totalPagesTransferred);

[`sqlite3_backup_finish()`]: https://www.sqlite.org/c3ref/backup_finish.html#sqlite3backupfinish

[`sqlite3_backup_init()`]: https://www.sqlite.org/c3ref/backup_finish.html#sqlite3backupinit

[`sqlite3_backup_step()`]: https://www.sqlite.org/c3ref/backup_finish.html#sqlite3backupstep