I was playing around with the outliner concept.
What is an outliner?
In computer terminology, an outliner is a master-detail self-referencing multi-column tree. A tree is a linked list of nodes.
There are three primary keys used, one to identify the whole tree, one to identify the parent, and one to identify the child.
The terminating condition in the recursion is that (Parent Key = Child Key) stops the self-referencing.
It is master-detail but it seeks it's own data instead of using a second table.
It is multi-column, so you can store data in two or more columns.
What is the back-end database?
The back-end database for this outliner is MSSQL stored in a table.