We will create a new index which will aggregate the World database to make a count of Cities that have the same name in different countries and return the CountryId key for each city as a single document. The following screenshot illustrates the expected result:
Start Visual Studio and open the
RavenDB_CH05solution.Add a new class to the project, name it
Cities_SameNameand add the following code snippet:
Tip
We named the embedded class
ReduceResultby convention. You can choose any other name for this class and place it outside the index class.We could use a
Stringtype in theReduceResultclass to store the document IDCountriesId(which is astringtype), but we choose to create a second embedded class, for learning purposes and show that it is possible to create more complex structure.Add a default constructor to the
Cities_SameNameclass and within this constructor add the indexMapfunction using the following code snippet...