During the Xmas holidays I found the time to have a look at MongoDb a Document oriented Database where the schema is based on JSON.

I downloaded the binaries and the C# Driver and I started some experiments.

The setup-time is minimal, the server is a console application that remain ready on a certain port:

D:\mongodb-win32-x86_64-1.2.1\bin>mongod.exe --dbpath ./data


Tue Jan 05 19:16:20 Mongo DB : starting : pid = 0 port = 27017 dbpath = ./data m

aster = 0 slave = 0  64-bit

Tue Jan 05 19:16:20 db version v1.2.1, pdfile version 4.5

Tue Jan 05 19:16:20 git version: 45992de574979343f34fdfe96b069d5d1eff0182

Tue Jan 05 19:16:20 sys info: windows (6, 0, 6002, 2, 'Service Pack 2') BOOST_LI

B_VERSION=1_39

Tue Jan 05 19:16:20 waiting for connections on port 27017

Above I simply specified the data folder even if there are a lot of parameters you can set.

The first sample that I write is this:

Mongo mongo = new Mongo();

mongo.Connect();

Database db = mongo.getDB("MyTestDb");

IMongoCollection posts = db.GetCollection("Persons");


Document doc = new Document();

doc["Name"] = "Emanele";

doc["Surname"] = "DelBono";

posts.Insert(doc);



Document example = new Document();

example["Name"] = "Emanuele";

ICursor cursor = posts.Find(example);


foreach (Document document in cursor.Documents)

{

  Console.WriteLine(document.ToString());

}

The first block is needed to open the “connection” to the database and to select with collection to work with.

Then I create a new Document and I fill in the key value pairs. The Document class is a dictionary that keep the document data and in JSON format and is converted BSON by the driver when the insert instruction get called.

The third block is a query to the database. I created a new document with a property name and the needed value, the Find method get a cursor from the database with all the matching document (i.e. all the persons whose name is Emanuele).

The power is in the storage and query method. You can create a complex document (with sub-documents, collection and so on) and store like a simple document.

This is a very first basic example on how to setup and run a micro-application on MongoDb, I’m now working on an extension to transform domain model objects in Document hierarchies so I can avoid the manual mapping from a Person class to the Document class.

Maybe in a next post I’ll talk more about that.