Need help with a validation rule
Hi, I'm a Access/VBA newbie and hit a problem while doing a project.
I'm building a table right now for 'product types', and each type can, but not necessarily has to, have a reserved range of 'drawing numbers'. So basically 3 fields: type, starting number, end number.
My problem is when I want to enter a new product type via a form, I have to make sure that the range entered for the new record does not clash with any other record.
E.g. Record A reserved 10000<x<20000, Record B reserved 20000<x<30000, so a new record C cannot have either the starting or the end drawing number in any of these ranges.
The catch is sometimes there might be gaps in the reservation. So say A reserved 10000<x<20000, B reserved 40000<x<50000, C can reserve any range within 20000 - 40000
Anyone have any idea how to go about this? Any help is appreciated