Need help please: update current record from previous record
i am not quite a newbie at FMP, but not particularly advanced either. Can I please have some assistance with the following - I need to do some complex calculations and don't know whether my database is set up right.
To calculate wine blends:
One wine blend has many operations.
A transfer operation has an EX tank, initial volume and final volume for a BLEND ID and a TO tank, initial volume and final volume for a BLEND ID (which may be the same or different, and will be manually assigned). The transfer operation may also be a despatch or bottling operation, in which case there is no To tank record.
If I assign an EX TANK, I need to find the previous record containing that tank in the TO tank, and look up the To Final Volume AND the To Blend code. If EX blend ID in the current record matches TO Blend ID in the previous record, I need to copy the volume to the Current EX tank initial volume, otherwise run a warning script asking whether the transfer will proceed because the blends are different. Can I nest logic commands?
I am currently using a portal to test the operations to the blend code, but eventually once working I would prefer to open a new window to enter the operations as this will be more user friendly.
Can you please assist me with the structure? I have created a duplicate table for selfjoin but don't quite know how to use this. Is this how I should proceed? If so, I'm a little lost as to the formulae I should use.
Your help would be appreciated.