I have written a class to represent ‘Treeview-like’ data, which can be simplified as:

public class Item {     public string Name { get; set; }     public KPI AssociatedKPI { get; set; }     public List<Item> Children { get; set; } } 

To each ‘branch’ of the Tree, can be associated a KPI, which can be simplified as:

public class KPI {     public string Name { get; set; }     public double Value { get; set; } } 

My database looks like

+------+-------+ + Name + Value + +------+-------+ + foo  +   5   + + bar  +  4.56 + +------+-------+ 

The tree structure, with the names of the KPIs is supposed to be filled in already.

I am struggling to decide where I should put the method to fill the values of the KPIs.

• First solution: In the KPI class

SELECT value FROM KPI WHERE NAME = 'foo'

It seems like it respects the SRP, the KPI class is responsible for the values of the KPI.

However, each KPI is unaware of the existence of others, and I need to have as many queries as I have branches in my tree.

• Second solution: In the Item class

I would get the names of all the KPIs in the descendants of this Item, and get a query looking like

SELECT Value FROM KPI WHERE Name IN ('foo', 'bar')

This way, I only need one per root of the tree (so usually, a single one).

My concern is that it breaks SRP, the Item should not be in charge of setting the values, should it?

In conclusion:

What would be the best way of doing it? Is there a third, better way I did not think about?

In this case, performance is not really an issue, the table and the tree are small, but I am learning, and would like to learn about the best practices.

Thanks,