Time for action – using the TransformResults function

You will create a new index class, then add a Map and TransformResults function. The index definition will contain only one Map function that retrieves the city population. Once the index is created you will execute it in Management Studio and view the result.

1. Open the RavenDB_CH05 project in Visual Studio.

2. Add a new class, name it TransformationResult and complete it with the following code snippet:

   

3. Add a new class, and name it Cities_ByPopulation and complete it with the following code snippet:

   

4. Add the following code snippet to the Main() method in the Program class:

   

5. Save all the files, build and run the solution.

6. In Management Studio, execute the Cities/ByPopulation index and observe the result.

What just happened?

You just created the Cities_ByPopulation index and implemented its Map function and TransformResults functions in order to transform the Map function result and get something different from the original Map result.

We begin by...