i want to implement an undo/redo system for an application. The data for this application i will get from my MySQL database. The data are hierarchical data similar to filesystem-data. I implement it in the database with the nested set model.
So here is my question: Does anyone out there have an idea how i could use the database to make an undo/redo system. For example: When i delete an entry (or a complete subtree) i want to 'undo' this action (if posible unlimited undo's).