I need to create a web report where users enter a list of parent part numbers then the report recursively collects all the material parts going into each of those, then goes through the total list determining which base material parts are unique and which ones are common to more than one parent part.

For example, someone enters the parent parts 'Peanut Butter Sandwich', 'Potato Chips'. Round 1 would result in 'Peanut Butter', 'bread', 'jelly', 'potato slices',... Round 2 would result in 'Peanuts', 'sugar', 'flour',...
Once the full list was collected, a grouping query would be done and those materials linked to more than one parent would be marked.

I did something similar to this in classic asp using a SQL Server table - adding records with the user's session id as a key field. I don't have that option this time, as the report is to be based on an Oracle database where I only have read access.

Any ideas? Is there any feature in .net that would allow manipulating a recordset in memory?