Greetings
I'm sure this subject must have been addressed in the past but I would be grateful for some thoughts on it.
On the attached .pdf file diagram I have shown :-
1. a typical "top-down" tree structure (similar to a Bill of Materials but without the frills of including the number of a particular part that's required in the makeup of the item in the next level up)
2. How the structure is logically modelled
3. How the data would by physically held in a normalised table.
The problem I've encountered in ACCESS is how to set up the one-to-many relationship from the Parent to the Child. This can be done but if a try to force referential integrity (so that the "1" and the "∞" symbols are displayed at the ends of the relationship line) I am informed that this is not valid because "No unique index found for the referenced field in the primary table"
I am sure I've managed to do this in the distant past (not in ACCESS though) and I can't understand why, what is perfectly logical, cannot seem to be achieved or accepted in ACCESS.
Any thoughts would be gratefully received.
I'm sure this subject must have been addressed in the past but I would be grateful for some thoughts on it.
On the attached .pdf file diagram I have shown :-
1. a typical "top-down" tree structure (similar to a Bill of Materials but without the frills of including the number of a particular part that's required in the makeup of the item in the next level up)
2. How the structure is logically modelled
3. How the data would by physically held in a normalised table.
The problem I've encountered in ACCESS is how to set up the one-to-many relationship from the Parent to the Child. This can be done but if a try to force referential integrity (so that the "1" and the "∞" symbols are displayed at the ends of the relationship line) I am informed that this is not valid because "No unique index found for the referenced field in the primary table"
I am sure I've managed to do this in the distant past (not in ACCESS though) and I can't understand why, what is perfectly logical, cannot seem to be achieved or accepted in ACCESS.
Any thoughts would be gratefully received.