I'm trying to set the Id property of my class as combination of another 2 properties:
public class Student
{
public string Id {get;set;}
public Guid StudentNumber {get;set;]
public string SchoolId {get;set;}
}
I want that StudentNumber and SchoolId to be the Id of the object when I save it.
How can it be done?
Have a look at the IdGenerator classes to custom create an id from the two properties.
http://docs.mongodb.org/ecosystem/tutorial/serialize-documents-with-the-csharp-driver/
You'll need to create a new IdGenerator class which implements the IIdGenerator interface (docs). There are two simple methods to implement.
Do note that a document's _id cannot be changed once saved. You'd need to resave it as a new document. So, if the SchoolId property changes, you may need to recreate the document.
Also, you might just consider creating a composite index for the two fields and leave the _id as an ObjectId.
