First Steps with RavenDB

By gamlerhart June 23, 2011 RavenDB

Ok, I’m starting another blog post series about a database. This time it is RavenDB, a document database. RavenDB is one of my favorite databases. In my opinion RavenDB has a very compelling combination of features. It stores JSON documents, supports transactions, it has very interesting query/indexing strategy (more in a later post), a well designed client-site API and good tooling. The only big drawback and yet a strength is that RavenDB was specifically designed for the .NET platform.

Introducing: RavenDB

Downloading / Installing Raven DB

You can download RavenDB here. It’s just a zip-file which you can unzip at any location. After that you can just run the ‘Start.bat’-file. It will start up RavenDB and open the administration console in the browser. That’s it, you have a RavenDB server running.

Adding Raven to you Solution

The next step is to add the client API to your solution. You either can reference the assemblies which are shipped with the RavenDB download. The ‘Client’-folder contains the assemblies for .NET 4.0, the ‘Client 3.5’-folder for .NET 3.5 and the ‘Silverlight’ folder Silverlight 4.0. Even better you can use NuGet and grab the ‘RavenDB’ package.

Storing Documents

First let’s create a class which we want to store. Like this person class:

class Person { public Person(string name, string sirName) { Name = name; SirName = sirName; } public string Name { get; set; } public string SirName { get; set; } }

Now let’s use RavenDB to persist data. First we create a document-store instance. This document-store allows us to create sessions for doing work. Each session is basically a unit of work on the database side.

using (var documentStore = new DocumentStore(){Url = "http://localhost:8080"}.Initialize()) { using (var session = documentStore.OpenSession()) { // do stuff } }

So let’s store our first document. Call the Store()-method and pass it the person object. After that we call .SaveChanges() to commit our changes.

using (var documentStore = new DocumentStore(){Url = "http://localhost:8080"}.Initialize()) { using (var session = documentStore.OpenSession()) { session.Store(new Person("Roman", "Stoffel")); session.SaveChanges(); } }

Store a Document

Query Documents

Queries (and Indexes) are written in LINQ in RavenDB. Queries and Indexes work quite different in RavenDB than in most databases. However this difference will be the topic for another blog post. For now we just query for our stored Person document.

using (var session = documentStore.OpenSession()) { var persons = from p in session.Query<Person>() where p.SirName == "Stoffel" select p; foreach (var person in persons) { Console.Out.WriteLine("Hi, here's {0} {1}",person.FirstName,person.SirName); } }

Query Documents

Update Documents

Updating documents is also easy. Query for the document, change the data you want and call .SaveChanges() to commit the changes.

using (var session = documentStore.OpenSession()) { var person = (from p in session.Query<Person>() where p.SirName == "Stoffel" select p).First(); person.FirstName = "More awesome Roman"; session.SaveChanges(); }

Update Documents

Delete Documents

Of course we also can delete documents. First call the .Delete() method and pass it the document to delete and then commit the changes with .SaveChanges().

using (var session = documentStore.OpenSession()) { var person = (from p in session.Query<Person>() where p.SirName == "Stoffel" select p).First(); session.Delete(person); session.SaveChanges(); }

Delete Documents

Documents? Tell Me More.

So far we stored person-objects / documents, ran a query and updated a person. At this stage is nearly looks like RavenDB is an object-database (like db4o). That’s why next time I will go into the concepts of RavenDB. Stay tuned.

Tagged on: .net, RavenDB

5 thoughts on “First Steps with RavenDB”

moldy June 24, 2011 at 2:56 pm

I had to add session.SaveChanges(); to the storing documents code
Tamayi June 24, 2011 at 5:12 pm

Really interesting! I just found out about RavenDB 5 minutes and I already love it! Looks really simple. Could certainly make use of it in a couple of places!
gamlerhart Post authorJune 25, 2011 at 1:45 am

Oups, yes…missed that in the code-snippet. Fixed.
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