Tonight we had a very different WAN Party. I have been wanting to learn about document databases for a long time. I tweeted about it the other day and someone mentioned that we should do it together on the WAN party. I thought that was a great idea, so tonight we went about implementing it. I used some screensharing software to show everyone my desktop, then all together we went about removing Linq-to-SQL and adding MongoDB to http://bundl.it. It didn’t take us too long, and we all got to learn together. It was really great, and I hope we can do this more often.
Anyway, I thought it would be a good idea to share what we learned here. MongoDB seems pretty awesome from the little I’ve used it (basically just tonight). You are able to map your objects and store them in really simple ways.
We used these blog posts as references for our education session: Jason Alexander's,
So, the first thing you do is download the executable for Mongo here.
I then opened Mongod.exe to get the server running on my machine, and then mongo.exe to look at and play with our data. What I did next was find a driver so I could access my data from my application (http://bundl.it is written in ASP.NET and C# MVC 3.5 Framework). Someone suggested Norm, it’s a project by Rob Conery and it seemed like it would be up for the task. We downloaded the repo, opened the project, and built it in Release mode. We then went over to the bundl.it solution and included the Norm.dll.
Ok, so, next step was replacing Linq-to-SQL in the bundl.it solution. I gutted all my data access methods, the idea was to get the application back up and working again using MongoDB. The next step was mapping out some classes. There was much dismay at my “BundleManager” class, also my throwing two objects in one class file, however this was for the sake of time and will be fixed before I deploy.
The ease of setting up my objects to Save and Request from MongoDB was suprising. Norm provides a connector class “MongoQueryProvider” within which you pass the name of your datastore as a string. The cool thing is if you haven’t created that particular store yet it will create it for you.
Step next was making sure my objects saved. The syntax on that was “mongoQueryProvider.DB.GetCollection<T>().Insert(object)” or “mongoQueryProvider.DB.GetCollection<T>().Save(object)” (this also does an Update). Retrieving them was just as easy: “mongoQueryProvider.DB.GetCollection<T>().FindOne(new Object {Property = property})”
One thing I loved was the ability to find a list of child objects by passing in the parent using “mongoQueryProvider.DB.GetCollection<Child>().Find(new Child() {Parent = new Parent() {ParentProperty = parentProperty}})” I didn’t have to map out these relationships in a painful ORM manner.
I don’t have enough experience with MongoDB to accurately cover the bonuses and pitfalls. However, the little I have worked with so far I really have enjoyed.
I’m going to make a “tldr;” how-to below to make life easy:
Step 1: Download the mongo executables and unzip.
Step 2: Run the mongod.exe from your command line
Step 3: Run the mongo.exe from your command line
Step 4: Download NoRm
Step 5: Build the NoRm project and Release
Step 6: Include the NoRm dll in your project
Step 7: Create a MongoQueryProvider
Step 8: Add new object
Step 9: Update existing object
Step 10: Retrieve object
Bonus step: Retrieve children via parent.
I plan to do the same “learn together” format for the next WAN. I have an idea of what we will learn, but if you have any desire one way or another let me know.
