Best Practices - Strategy - Versions

[mike arcon]

Hey there,

I'm thinking about possibilities to Build in my Project(s) an backward compatibility to the Database.

Example

At the Beginning we have 1 Model and 1 Controller (ignoring the View right now).

the Model has 1 Field

public class EmployeeModel
{
    String address;
    
    public EmployeeModel() {
        
    }
    
    public void setAddress(String address) {
        this.address = address;
    }

}

the Controller uses this Class Employee:

public class EmployeeController
{
    public EmployeeController() {
        EmployeeModel emp = new EmployeeModel();
        
        emp.setAddress("what ever 123456");
    }
    
}

Now we enhance the Database to Model with 2 Fields:

public class EmployeeModel
{
    String address;
    int code;
    
    public EmployeeModel() {
        
    }
    
    public void setAddress(String address) {
        this.address = address;
    }
    
    public void setCode(int code) {
        this.code = code;
    }

}

the new Controller will be:

public class EmployeeController
{
    public EmployeeController() {
        EmployeeModel emp = new EmployeeModel();
        
        emp.setAddress("what ever");
        emp.setCode(123456);

    }
}

and now the Question:

let's say there are more than one version in use.. older and new one...and you want to have both versions available...how do you will handle this? what are your experience?

I'm thinking about an Interface which maps to the corresponding actual fields...

example:

Class Controller EmployeeV1(String adress)
String adress = substring(0, index.of(" "));
int code = substring(index.of(" "), adress.length);
...setAdress(adress)
...setCode(code)

Class Controller EmployeeV2(String adress, int code)
...setAdress(adress);
...setCode(code);

pseude code but i think the strategy should work but I think there should be better ways?