how to load nodes in treeview from a datatable of unique category codes having parent code, using recursive method?

Hi, Please tag your question to indicate whether this is WinForms or WPF or ?

Most important question: when you use the word "ROOT" are you talking about a TreeView with one Root Node which has, as its child Nodes, all other Nodes whose parent_category_code is "ROOT:" or: are you talking about a TreeView with multiple root Nodes ?

And, please clarify why the last entry shown has "ROOT" both as parent_category_code and category_code: what does that mean in terms of what you want displayed in the TreeView ?

What does it mean that "ML" appears both to be a root Node, and a child of a (or the only) Root Node ?

Another question: wouldn't it be easy to sort the DataTable so all the Root nodes appeared first ?

The best way you could improve this question is to show us, visually, the result you want to see by simulating a view of the resulting TreeView: you can do this inside your original question by using pre-tags where you can use indent.

I believe a non-recursive solution is possible here, but until you've clarified the question, I am not going to try to come up with some code.

Any answer I would give here would assume you had done the work to get your DataTable into an IEnumerable Form where you could traverse it with for, or foreach, and would assume that for each item in this IEnumerable, the three fields would be strings.

thanks, Bill