Workflow to limit the number of items based on date

Forum|Forum|6 years ago
July 8, 2020
4 replies
54 views

+3

danjact

I have a list (task with calendar) that will serve as a class signup sheet.

Since we're limiting the classes to 20 people, I am trying to write a workflow that is based on the following:

- For any date (class), if the number of people signed up is 20, you can no longer sign up for that date.

I'm very flexible on the structure of the list as well - We can change it to make it work. However, even with this, I'm having a hard time wrapping my head around the workflow and list, and how to make this work.

Any ideas?

T

+8

Tarf
Novice
Forum|Forum|6 years ago
July 9, 2020

Hi @danjact
are you sure there will be only one class per day?

Let´s say there could be multiple.

Create a List named Classes, make the Title unique
Create a List named Registrations (Person, Lookup to Classes:Title)
Add a Form to Registrations
- Add a calculated value with formula: lookup("Registrations","Class",your_Control,"ID",true).length
  - "Class" is the name of the lookup column and your_control is the lookup control on the form
  - This will show you how many registrations have already been made.
  - Now you can add validation as required.

If you do not need the Extra List for Classes, you could make the same formula work with a date field

lookup("Registrations","Date",your_Control,"ID",true).length
Please note that by doing the extra list, you gain advantages like