Typical asset fields like Manufacturer, Model Number, Serial Number, Year Mfg, Date Installed, Installed By etc are no longer in the Customer Asset table. This is a pain but okay as one can create these as 'custom' fields.
However, on the now custom Serial Number field, we need to ensure that it is unique to that Product code and error if it is not.
For example, HP produce a printer. Lets call it HP-LJ123 being the manufacturers model number. We would then create a product called HP-LJ123 in the products table.
In the Customer Asset screen, the customer could then be assigned an HP-LJ123 with serial number 123456
HP only made one machine with serail number 123456 and so logically I should only be able to create one Customer Asset record for that machine and serial combination.
In addition, lets assume HP also made a HP-LJ456. That too could have a serial number of 123456 but no two HP-LJ456's in the Customer Asset table can have a serial number 123456
So how can I ensure that the product , serial number combination is unique to police the data integrity i.e. not allowing a user to enter the machine twice.
