F# MongoDB sample (C# Driver)

gistfile1.fs

#I @"..\packages\mongocsharpdriver.1.8.3\lib\net35\"
#r "MongoDB.Driver.dll"
#r "MongoDB.Bson.dll"

open System
open MongoDB.Bson
open MongoDB.Bson.Serialization.Attributes
open MongoDB.Driver
open MongoDB.Driver.Builders
open MongoDB.Driver.Linq

type Tweet() = 
    member val Id = ObjectId.Empty with get, set
    member val ProfileImageLocation     = "" with get, set
    [<BsonDateTimeOptions(Kind = DateTimeKind.Local)>]
    member val CreatedDate              = DateTime.MinValue with get, set
    member val FromUserDisplayName      = "" with get, set
    member val FromUserScreenName       = "" with get, set
    member val ToUserDisplayName        = "" with get, set
    member val ToUserScreenName         = "" with get, set
    member val Text                     = "" with get, set
    member val TweetId                  = "" with get, set
    member val Source                   = "" with get, set
    member val Language                 = "" with get, set
    member val Location                 = "" with get, set

let tweets = 
    let collectionName = "fsharp"
    let client = MongoClient(@"mongodb://localhost")
    let server = client.GetServer()
    let database = server.GetDatabase("fsharp")
    let _collection = database.GetCollection<Tweet>(collectionName);
    let collection =
        if (_collection.Exists()) then _collection
        else database.CreateCollection(collectionName) |> ignore
             database.GetCollection<Tweet>(collectionName)

    query {
        for x in collection.AsQueryable<Tweet>() do
            select x }
    |> Seq.toArray

Greetings.
Despite this gist being useful as it is, I'd like to provide a more or less useful comment (for those who only starting with MongoDB) regarding this class construct. It is not longer necessary and can easily be replaced with a plain F# record type with [].