Data Contract for Two database Tables during Join Condition - sql

Question

I have 2 tables in my DB like Patient Table and Appointment Table
for which I have created 2 Data Contracts namely Patient,Appointment in my WCFREST Service.
I use List<Patient> to fill the DB Table info in the List object and
List<Appointment> to fill the DB Table info in List obj as well.
Here I have an Operation Contract which returns data from 2 tables using Join Statement
For that how should I store the result, because I have 2 different objects ?
Do I need to create one more DataContract by combining fields of these two tables?

Answer 1

Use Entity frame work (table first or model first approach). But as you already have tables available you might want to base your model on the tables. Whatever way you choose ultimately your Data Contract should look as below:
[DataContract]
public class Patient
{
[DataMember]
public int ID { get; set; }
[DataMember]
public string Name { get; set; }
[DataMember]
public List<Appointment> Appointments { get; set; }
}
[DataContract]
public class Appointment
{
[DataMember]
public int ID { get; set; }
[DataMember]
public DateTime AppointmentTime { get; set; }
[DataMember]
public Address Venue { get; set; }
}
Trick is to make DataContract for each of table. You don't have to create multiple data contracts to match your needs.
The service contract should be as below:
[ServiceContract]
public interface IPatientService
{
[OperationContract]
List<Patient> GetAllPatients();
}
you can then use the DbContext provided by the EF in combination with extensions (Dependency injection) as below. Or just get rid of the constructor if you don't want to go advanced with it and create _context object right on intialization. Here is a sample.
public class PatientService : IPatientService
{
HospitalDbContext _context;
public PatientService(HospitalDbContext _context)
{
this._context = _context;
}
public List<Patient> GetAllPatients()
{
return (from patient in _context.Patients
select patient).ToList<Patient>();
}
}
You are free to add LINQ conditions here to take joins and other operations as well.

Answer 2

[DataContract]
class A
{
[DataMember]
public string PatientName { get; set; }
// more stuff.
}
[DataContract]
class B
{
[DataMember]
public string HospitalName { get; set; }
// more stuff.
}
[DataContract]
class C
{
[DataMember]
public A prop1 { get; set; }
[DataMember]
public B prop2 { get; set; }
// more stuff.
}