// 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 (will create index in Age field)
	var results = col.Find(x => x.Age > 20);
}

// 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; }
	public decimal Total => Products.Sum(p => p.Price);
}        

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

// "Produts" 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
	.Index(x => x.OrderDate)               // Index this field
	.Ignore(x => x.Total);                 // Do not store this
            
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;
		...
	}
                    
}