LiteDB - A .NET NoSQL Document Store in a single data file

LiteDB is a small, fast and lightweight .NET NoSQL embedded database.

Serverless NoSQL Document Store
Simple API, similar to MongoDB
100% C# code for .NET 4.5 / NETStandard 1.3/2.0 in a single DLL (less than 450kb)
Thread-safe
ACID with full transaction support
Data recovery after write failure (WAL log file)
Datafile encryption using DES (AES) cryptography
Map your POCO classes to BsonDocument using attributes or fluent mapper API
Store files and stream data (like GridFS in MongoDB)
Single data file storage (like SQLite)
Index document fields for fast search
LINQ support for queries
SQL-Like commands to access/transform data
LiteDB Studio - Nice UI for data access
Open source and free for everyone - including commercial use
Install from NuGet: Install-Package LiteDB

New v5

New storage engine
No locks for read operations (multiple readers)
Write locks per collection (multiple writers)
Internal/System collections
New SQL-Like Syntax
New query engine (support projection, sort, filter, query)
Partial document load (root level)
and much, much more!

Lite.Studio

New UI to manage and visualize your database:

Documentation

Visit the Wiki for full documentation. For simplified chinese version, check here.

LiteDB Community

Help LiteDB grow its user community by answering this simple survey

How to use LiteDB

A quick example for storing and searching documents:

// Create your POCO class
public class Customer
{
    public int Id { get; set; }
    public string Name { get; set; }
    public int Age { get; set; }
    public string[] Phones { get; set; }
    public bool IsActive { get; set; }
}

// Open database (or create if doesn't exist)
using(var db = new LiteDatabase(@"MyData.db"))
{
    // Get customer collection
    var col = db.GetCollection<Customer>("customers");

    // Create your new customer instance
    var customer = new Customer
    { 
        Name = "John Doe", 
        Phones = new string[] { "8000-0000", "9000-0000" }, 
        Age = 39,
        IsActive = true
    };

    // Create unique index in Name field
    col.EnsureIndex(x => x.Name, true);

    // Insert new customer document (Id will be auto-incremented)
    col.Insert(customer);

    // Update a document inside a collection
    customer.Name = "Joana Doe";

    col.Update(customer);

    // Use LINQ to query documents (with no index)
    var results = col.Find(x => x.Age > 20);
}

Using fluent mapper and cross document reference for more complex data models

// DbRef to cross references
public class Order
{
    public ObjectId Id { get; set; }
    public DateTime OrderDate { get; set; }
    public Address ShippingAddress { get; set; }
    public Customer Customer { get; set; }
    public List<Product> Products { get; set; }
}        

// Re-use mapper from global instance
var mapper = BsonMapper.Global;

// "Products" and "Customer" are from other collections (not embedded document)
mapper.Entity<Order>()
    .DbRef(x => x.Customer, "customers")   // 1 to 1/0 reference
    .DbRef(x => x.Products, "products")    // 1 to Many reference
    .Field(x => x.ShippingAddress, "addr"); // Embedded sub document
            
using(var db = new LiteDatabase("MyOrderDatafile.db"))
{
    var orders = db.GetCollection<Order>("orders");
        
    // When query Order, includes references
    var query = orders
        .Include(x => x.Customer)
        .Include(x => x.Products) // 1 to many reference
        .Find(x => x.OrderDate <= DateTime.Now);

    // Each instance of Order will load Customer/Products references
    foreach(var order in query)
    {
        var name = order.Customer.Name;
        ...
    }
}