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Helper I
Helper I

Subtract Available Seat

Hi guys,

I'm struggling to subtract the seat. I have built 2 SharePoint lists. 

List A

  • Flight Name (Text)
  • Available Seat (num)


List B

  • Flight Name (text)
  • Total Seat Reserved (num)

On the PowerApps 

Screen 1: Gallery 

Datasource: List A


Screen 2: Form

Datasource: List B

Field: Seat Reserved input 


How do I subtract the available seat from the gallery I selected? when I submit the form the number will change in the List A


For instance:

Available Seat = 5 

Seat entered = 2

Remaining seats 3



Super User
Super User

I wonder if two lists are creating some confusion for you in this situation? If I were attacking this problem, I would create a single list called Seats with the following columns:




Status (which can be blank, Reserved, or Unavailable)

...and other handy info like flight date, seat class, passenger name, etc.


Then, I would use a Filter to display seats that are not Reserved status on the flight, meaning they could be reserved by a customer. I could also use a Countrows on a Filter of 'blank' Status to know how many seats are left on that flight.


Or, is there more to your situation that makes it more complicated?



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