You will create a new index definition (Countries_Population) which will return the population sum for each Country in the World database. Then you will register this index automatically within the application startup.
Open the
Worldproject, create a new folder and name itIndexes.Add a new class to the
Indexesfolder and name itCountries_Population.Modify the
Countries_Populationclass as follows:
Modify the
RavenStoreclass to call theCreateIndexes()method:
Save the
Worldapplication and press F5 to build it and run it.
You just modified the World application in order to automatically create the Countries_Poupulation index on the World database.
You began by creating the Countries_Poupulation index definition. This index defines a Map/Reduce function that retrieves the Population for each City Id and then aggregates them by Country Id.
Then within the RavenStore class (in World.DAL), you call the CreateIndexes() method...