CRUD Operations

CRUD stands for Create, Read, Update, Delete – the four basic operations every database must support. file-json-db provides both synchronous and asynchronous versions of each.

Create – Insert

insert(document) sync

Insert a single document. Returns the inserted document (with generated ID if applicable).

const user = users.insert({
  name: 'Alice',
  email: 'alice@example.com',
  age: 28
});
console.log(user._id); // → 1 (if autoId is true)

insertAsync(document) async

const user = await users.insertAsync({
  name: 'Bob',
  email: 'bob@example.com'
});

Async inserts go through the collection’s internal lock/queue, so concurrent async writes on the same collection are serialized.

insertMany(documents) / insertManyAsync(documents)

Insert an array of documents in one go. Returns the array of inserted documents.

const inserted = users.insertMany([
  { name: 'Carol', email: 'carol@example.com' },
  { name: 'Dave',  email: 'dave@example.com' }
]);

// Async version
const inserted2 = await users.insertManyAsync([
  { name: 'Eve', email: 'eve@example.com' }
]);

Read – Find

findOne(query) / findOneAsync(query)

Return the first matching document, or null if none match.

const user = users.findOne({ email: 'alice@example.com' });
const user2 = await users.findOneAsync({ name: 'Bob' });

find(query) / findAsync(query)

Return a QueryBuilder. You must call .toArray(), .first() or .count() to get the actual results.

// All adults
const adults = users.find({ age: { $gte: 18 } }).toArray();

// First match only
const first = users.find({ active: true }).first();

// Just the count
const total = users.find({}).count();

// With limit / sort
const page = users.find({ active: true })
  .sort({ name: 1 })
  .skip(20)
  .limit(10)
  .toArray();

Update

updateOne(filter, update) / updateOneAsync

Update the first document that matches the filter. Returns the updated document or null.

users.updateOne(
  { email: 'alice@example.com' },
  { $set: { age: 29 }, $push: { tags: 'verified' } }
);

updateMany(filter, update) / updateManyAsync

Update every document that matches. Returns an array of the updated documents.

const updated = users.updateMany(
  { active: false },
  { $set: { status: 'archived' } }
);
console.log('Updated', updated.length, 'documents');

Full details of update operators ($set, $inc, $push, …) are on the Update Operators page.

updateFunc / updateFuncAsync

For complex logic you can supply a function that receives the document and returns the new version (or mutates it):

users.updateFunc(
  { role: 'member' },
  (doc) => {
    doc.points = (doc.points || 0) + 10;
    doc.lastBonus = new Date().toISOString();
    return doc;
  },
  { multi: true }   // update all matches
);

Delete

deleteOne(filter) / deleteOneAsync

Delete the first matching document. Returns the deleted document or null.

const removed = users.deleteOne({ email: 'bob@example.com' });

deleteMany(filter) / deleteManyAsync

Delete every matching document. Returns an array of the deleted documents.

const removed = users.deleteMany({ active: false });
console.log('Deleted', removed.length, 'inactive users');

Summary of methods