rmunn / mongodb.fsharp

Silent utilities to make the official MongoDB driver feel natural to work with in F#

This project takes the official .NET MongoDB driver and fixes the warts that make it hard to work with in F#. By default, F# loves immutable types but the MongoDB driver can't handle them out of the box. F# collections like list, map and seq aren't properly

Installation

Note also that this requires at least version 1.8.1 of the official MongoDB driver. That version includes some API that makes this whole project possible.

Install NuGet and run this from the Package Manager Console.

PM> Install-Package MongoDB.FSharp

To use the C# driver just type

open MongoDB.Bson
open MongoDB.Driver

Somewhere during startup you have to register MongoDB.FSharp. It's basically a one-liner that looks like:

open MongoDB.FSharp
Serializers.Register()

The Serializers.Register() call just registers serializers with the MongoDB driver.

Usage

Use MongoDB.FSharp like you normally would in C#.

type Person = { Id : BsonObjectId; Name : string; Scores : int list }

let connectionString = "mongodb://localhost"
let client = new MongoClient(connectionString)
let db = client.GetDatabase("test")

let collection = db.GetCollection<Person> "people"

let id = BsonObjectId(ObjectId.GenerateNewId())
do! insertOne collection { Id = id; Name = "George"; Scores = [13; 52; 6] }

let! george = findOneById collection id

The example above would work naturally in C#, but remember that record types like Person are immutable! With MongoDB.FSharp, this just works.

What's Implemented

Serializing and Deserializing these items should work great:

• list
• Options
• Discriminated unions
• Records

Road Map

• Better support for Linq and quotations
• A functional API for simpler access
• Better testing so you can be confident putting this in production