Import & Export

You can load documents from an external JSON file into a collection, and you can export a collection by simply reading its part files or by using a backup with the pack option.

Import

collection.import(filePath, options?) reads a JSON file and inserts its documents into the collection.

Accepted file shapes

• A top-level JSON array of documents
• An object with a data or documents array property

// users.json
[
  { "name": "Alice", "email": "alice@example.com" },
  { "name": "Bob",   "email": "bob@example.com" }
]

// or
{
  "documents": [
    { "name": "Alice", "email": "alice@example.com" }
  ]
}

Usage

// Append the file contents to the collection
const ok = users.import('./seed/users.json');
console.log(ok); // true on success, false on error

// Clear the collection first, then import
users.import('./seed/users.json', { clear: true });

// Async version (goes through the lock)
await users.importAsync('./seed/users.json', { clear: true });

On success the collection emits an import event with { collection, count }.

Options

Export

There is no dedicated export() method because the data is already plain JSON on disk. You have three practical options:

1. Read part files yourself

const fs = require('fs');
const path = require('path');

function exportCollection(collectionPath, outFile) {
  const parts = fs.readdirSync(collectionPath)
    .filter(f => f.startsWith('part-') && f.endsWith('.json'))
    .sort();

  const all = [];
  for (const part of parts) {
    const docs = JSON.parse(fs.readFileSync(path.join(collectionPath, part), 'utf8'));
    if (Array.isArray(docs)) all.push(...docs);
  }
  fs.writeFileSync(outFile, JSON.stringify(all, null, 2));
}

exportCollection('./data/users', './export/users.json');

2. Use find().toArray()

const docs = users.find({}).toArray();
fs.writeFileSync('./export/users.json', JSON.stringify(docs, null, 2));

3. Backup with pack: true

The database backup method can pack every collection into a single JSON file per collection (see the Backups page).

db.backup('./exports', { pack: true });
// creates ./exports/users/users.json, ./exports/orders/orders.json, …