Take a look at the other nodes first, but as a supplement/alternative, consider building two tables. In the first table, define a "node" and give each node a unique ID. In the second table, define parent-child relationships. I.e. for every child that a parent has, we will see one row in the second table with the parent's ID and the child's ID. When you wish to get a list of children for a parent node, just select child ID's from the 2nd table where the parent ID equals the current node's ID.