Nested classes query and join - linq

Question

I have the following situation, in this case I am looking flattening the nested objects and combine parent and child fields in a single row, instead of creating objects parent and child.
Also I want to combine v1 and v2. Any Advice?
public class Person
{
public string idPerson;
public string names;
private List<Subject> subjects = new List<Subject>();
private List<MedicalRecord> medicalRecords = new List<MedicalRecord>();
}
public class Subject
{
public string subjectName;
public string subjectId;
}
public class MedicalRecord
{
public int recordId;
public string doctorName;
public string medicalCare;
}
void main()
{
/// Assume that Person is filled.
/// How can I join the two lists?
List<Person> all = new List<Person>();
var v1 = all.SelectMany(p => p.subjects, (child, parent) => new { child, parent });
var v2 = all.SelectMany(p => p.medicalRecords, (child, parent) => new { child, parent }); /// here i want to select all fields instead of objects to avoid child and parent calling from below cycle.
/// I want to join v1 and v2 and flatten the lists.
foreach(var obj in v1)
{
Console.WriteLine(obj.child.subjectName + " " + obj.parent.idPerson);
}
///
}

Answer 1

You need to do as follows:
static void Main(string[] args)
{
List<Person> all = new List<Person>();
// Estract the flattened list of subjects
var subjects = all.SelectMany(p => p.Subjects, (person, subject) => new { person.idPerson, person.names, subject});
// Estract the flattened list of medical records
var medicalRecords = all.SelectMany(p => p.MedicalRecords, (person, medicalRecord) => new { person.idPerson, person.names, medicalRecord});
// Join the two lists and create a flattened object
var flattenedList =
subjects.Join(medicalRecords,
s => s.idPerson,
m => m.idPerson,
(s, m) => new {
IdPerson = s.idPerson,
Names = s.names,
s.subject.SubjectId,
s.subject.SubjectName,
m.medicalRecord.RecordId,
m.medicalRecord.DoctorName,
m.medicalRecord.MedicalCare
})
.ToList();
}