There is a lot of talk lately in the .NET community of using a document database instead of the traditional relational database. Although I’ve kept up on the reading I haven’t invested any time trying it out for myself. Today I decided to give it a shot and considering the amount of time it took me to get things up and running I’m impressed.
First off go install MongoDB. Download Page
The install couldn’t be much simpler for me. Extract the files and run the server.
Then go download the source for NoRM and compile.
Start up a new project and begin define your class(es).
Then define your mapping. This step is optional it appears, however, I’m a fan of the NHibernate style of keeping persistence depedencies like identifier types, etc out of your model so I’m starting off this way.
There currently doesn’t appear to be a lot of options for mappings, mostly because there isn’t a need for lots of options. However, I would like to specify DbReference<T> in this class as well. DbReference<T> is a way to specify that the relationship of <T> is another document. Unfortunately it doesn’t appear to be supported (unless I missed something). If I get further along using NoRM this is likely something I would want to add.
Next is a sample usage of the simple model defined.
Obviously this sample isn’t ground breaking. However, I was able to download and install, compile NoRM, and put together a sample in under 10 minutes. I would say try doing that with SQL Server. The install alone takes longer than 10 minutes.
Open questions that I have that I intend to cover in the coming weeks.
- What is NoRM doing under the covers?
- How easy will it be to extend the behavior I described earlier when relating to other documents?
- How does searching against a document database change things. Can I do things like p.FirstName.StartsWith(“f”)?
- How well will a document database fit in with event sourcing. If it does, is it enough to have “persisted index” approach to get the current document(s) or is better to still keep that code close to the command persisting the event?
- Do you readers have others?