>Try it. [snipped example]
Ah. Basically, you set up the rule to assign every column, and if the update
doesn't redefine some columns, then it still works. I didn't understand that
you could get the rule to work generically like this.
I'll presume that the rule will need amending if the table column definition
later changes. (E.g. if I add 'stalk_length' to my apples and pears
tables)...
Thanks very much for your help.
Andy