Question

I have a table with UserId and ManagerId. When Editing this table I need to make sure that
if Jim is Jills manager, and Ron is Marks manager, then I should not be able to set Mark as Jim manager, because it would create in infinate loop. I want to validate a form that can set a Manager field to a UserId.

Answer 1

I dont see an infinite loop there… Ron is Marks manager, Jim is Jills Manager. If you set Mark as Jims manager, then you would have a linear tree of management. Ron->Mark->Jim->Jill. No need for recursion 🙂

I understand what your trying to accomplish, but more information would give better insight to help you. Are these Employees a class or an entity of a table?

I’m assuming each employee will only have one manager. Therefore, when setting an employee as another’s manager, progress up the linear tree to see if it would be valid, like so:

//Assume managerName is "Mark" and employeeName is "Jim", as in your example above
public bool isManagerValid(string managerName, string employeeName)
{
    bool valid = true;
    var manager = getEmployee("Mark"); //The "to-be" manager of Jim
    var employee= getEmployee("Jim");

    var currentManager = getEmployee(manager.Manager); //Get Marks manager
    while(currentManager != null && valid)
    {
        if(currentManager == employee)
        {
            valid = false; //Some manager up the line from Mark is already Jim 
        }
        else
        {
            //Get the next manager up
            currentManager = getEmployee(currentManager.Manager);
        }
    }
    return valid;
}

I didnt attempt this in visual studios, typed it in here, so if there are any typo’s, please excuse me