Hi, I’m so sorry to be repeating what other people have already asked, I have tried a few of the solutions previously suggested, but I am such a novice, I’m obviously doing something wrong. I’m hoping that if I give my specific examples someone really clever and very patient can give me a step by step idiots guide please. This is the simplified version:

Table A = purchase orders to buy various types of material
Table B = batches of material booked into stock (from the purchase orders)
Table C = customer orders to sell the material

These tables are linked so that every time a purchase order is completed (Table A) the material gets booked into stock (Table B) and the quantities increased accordingly, then every time a customer order is completed (Table C) it deducts the corresponding quantity from stock - so far so good.

In Table C there is a link to Table B check the stock levels and I want to also at this stage be able to see at a glance the price of the most recent batch purchased without having to go into Table A to find that information.

In Table B there is a lookup field showing the prices from the linked purchase orders in Table A, but they don’t show in reverse order so after a while the most recent values are no longer visible (I understand there used to be an option to reverse the order but it was removed for some reason such a shame).

Anyway, I’ve seen other answers saying to use this type of rollup function: IF(MAX(values) = {field name}, {field name}) and I managed to get as far as creating a rollup field on the material stock table B to show the date of most recent linked purchase order, but from there on it kept going horribly wrong. I either got error messages or simply no value returned.

Many thanks, Gill