Thin layer over MongoDB driver for .NET, it is thin as a crêpe! (hence the icon...). It is mostly extension methods and builders to allow querying MongoDB more easily. The goal of this library is to stay simple, more complex cases can be built upon.

The nuget package name is MongoDB.Thin: https://www.nuget.org/packages/MongoDB.Thin/

To add it to ASP.NET Core

services.AddMongo("YourConnectionString", "YourDatabaseName");

Example where _database is an instance of IMongoDatabase. And Game is the collection holding the games.

_database.Collection<Game>();

Get a document from a collection by supplying a filtering c# expression Example:

var game = await _games.FindOneAsync(g => g.Id == id);

Get a FindOneAndUpdate command by invoking FindOneAndUpdate() on your collection (IMongoCollection). You can then filter it multiple times, and perform multiple modifications.

• Filters are defined by calling Filter() on the command, the method accepts a lambda that configures the filter builder: C# filtering expression, C# expression with MongoDB operators, or a JSON string.
• Modifications are defined by calling Modify() on the command, the method accepts a lambda that configures the modification builder. Normal MongoDB operators can be used.
• Options can be defined by calling Options() on the command, the method accepts a lambda that configures the options builder. Projections can be defined, targeting array fields can be defined using WithArrayFilter.
• Finally awaiting ExecuteAsync runs it asynchronously.

Example:

var command = _games.FindOneAndUpdate();
command.Filter(b => b.Match(g => g.GameType == gameType &&
		 !g.Players.Any(p => p.Id == player.Id) &&
		 g.Status == GameStatus.WaitingForPlayers));

if (duration.HasValue)
{
	command = command.Filter(b => b.Match(g => g.MaxDuration <= duration));
}

var game = await command.Update(b => b
	.Modify(g => g.Push(g => g.Players, player))
	.Modify(g => g.Inc(g => g.Version, 1)))
	.ExecuteAsync();

Get an UpdateOne command by invoking UpdateOne() on your collection (IMongoCollection). The command is similar to FindOneAndUpdate, except that the options don't allow any projection (since no document is returned).

Indexes can easily be added using expressions.

Example:

var db = app.ApplicationServices.GetService<IMongoDatabase>()!;

db.Collection<Game>().Indexes
	.Add(g => g.GameType)
	.Add(g => g.Status)
	.Add(g => g.Players, p => p.Id);

Here Game collection got 3 indexes:

• GameType field ascending
• Status field ascending
• Players is an array, it got an index on Id field

You can see more usage examples in OnlineBoardz repository:

• GameRepository class
• TicTacToeRepository class