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Inheritance

Introduction
Any database object can inherit from any other database object. The Database attribute is inherited from base- to subclasses. Hence, any class that directly or indirectly inherits a class with the Database attribute becomes a database class.
Example
In this example, both PrivateCustomer and CorporateCustomer become database classes due to them inheriting Customer:
[Database]
public class Customer
{
   public string Name { get; set; }
}
​
public class PrivateCustomer : Customer
{
   public string Gender { get; set; }
}
​
public class CorporateCustomer : Customer
{
   public string VatNumber { get; set; }
}
The table Customer will contain all PrivateCustomers and all CorporateCustomers. So if there is a private customer called "Goldman, Carl" and a corporate customer called "Goldman Sachs", the result of SELECT C FROM Customer c will contain both of them.
Base Classes
A base class contains all instances of all derived classes in addition to the instances with the its own exact type.
SELECT C FROM Customer C WHERE Name LIKE 'Goldman%'
Returns [ { Name:"Goldman Sachs" }, { Name:"Goldman, Carl" } ]
Derived classes
SELECT C FROM PrivateCustomer C WHERE Name LIKE 'Goldman%'
Returns [{ Name:"Goldman, Carl", Gender:"Male" }]
SELECT C FROM CorporateCustomer C WHERE Name LIKE 'Goldman%'
Returns [{ Name:"Goldman Sachs", VatNumber:"1234" } ]
Inheriting From Non-Database Classes
A database class cannot inherit from a class that's not a database class. This will throw an error when the application is weaved.
It's also not possible to cast a non-database class to a database class.

Relations

Sharing data

Last modified 5yr ago