Sitecore: Follow relational links in Sitecore Query - sitecore

Question

I have an item structure that doens't correspond to "documents" in the standard Sitecore sense. It corresponds to data items.
One of the relationships that my items have is the following:
Person -> State -> Country
Where a Person has a link field to a State and state's have link fields to a Country.
My question is: How would one write a query to retrieve all of the People who have an eventual link to a Country of a certain abbreviation?
I'm stumped as to how to do it in Sitecore Query. My current solution is using LINQ and several queries.

Answer 1

Assuming that the links between these items where created using a Reference field, such as a Droplink, Treelist, Droptree, etc., you can traverse the references/referrers using the Sitecore Links database.
Here is an example (untested) that starts with a country item and fetches any referring states. The same query is performed on the states to fetch any referring people. The results are added to a generic List<Item> collection.
List<Item> peopleList = new List<Item>();
var countryReferences = Globals.LinkDatabase.GetReferences(countryItem);
var referringStates = countryReferences.Select(c => c.GetTargetItem()).Where(c => c.Template.Key == "state");
foreach (var state in referringStates)
{
var stateReferences = Globals.LinkDatabase.GetReferences(state);
var referringPeople = stateReferences.Select(s => s.GetTargetItem()).Where(s => s.Template.Key == "person");
foreach (var person in referringPeople)
{
peopleList.Add(person);
}
}