Need Help with Action Expression

Hey all

Hope you guys having great day, I’m really new to Appsheet. Currently work with a spare management app

I have 2 tables in appsheet db Spares, Spare Usage

Spares:
Row ID - Text - Key
Spare ID - Text - Unique()
Machine/Area - EnumList (So my user can add multiple machines for same spare instead of multiple entries)
Part & Specification - Text
Category - Enum eg: Mechanical,Eletrical
Available Stock - Number
Unit - Enum (Kg,Mtr etc)
Spare Usage:
Row ID - Text - Key
used-transaction id - text
Machine/Area - Enum (Cause a spare will be using for a machine at a time)
Part & Specification - Enum (In my spare usage form I used this expression SELECT(Spares[Part & Specification], IN([_THISROW].[Machine/Area], LIST([Machine/Area]))) to filter the Part & Specification according to the Machine/Area
Category - Text - read Only (When Machine - Parts matches it’ll show appropriate Category
Available Stock- Number - same as Category
Used Stock - Number

Now My query is When the Usage Spare form is submitted the Used Stock need to be reduced from the Available Stock in Spares table. I have tried something with help of AIs but none of them seems effective . Hope someone can point me to correct direction

You will need to use the INPUT(). It has two uses one of which is to pass values from one action another. It was created specifically to address the issue you are facing.

I hope this helps!