I've created a custom list in my SharePoint to allow users select a table reservation for our Christmas dinner.

My columns are just; "Name" and "Table Choice", "Table Choice" field has 16 different tables to select.

But 1 table can only have 10 person max so I'd like to Show a warning message if a user tries to reserve an already filled table.

Thanks in advance.

  • I'd fan out the seats, one seat to every list item, like "Table 1 Seat 1", "Table 1 Seat 2". Then you can have people assign themselves to another column, "Assigned To", or something of that nature.
    – Mike
    Dec 11, 2017 at 14:29

2 Answers 2


I can think of a couple ways to handle this scenario.

  1. Setup a workflow to handle when the a table is full to remove it from the options table.
  2. Use some jQuery and add it to the new and edit forms to check if a table is full when they select a value. Then you could display a message.

Idea based on Mike’s suggestion. You can use “enforce unique values” feature to prevent users from duplicating data.

  1. Create a “Seat Choice” column for 10 seats.

  2. Create a text column named “Your Seat”.

  3. Using JavaScript to set seat (“Table Choice” value and “Seat Choice” value) to “Your Seat” and make it read-only. Or, using InfoPath form to set the default value.

enter image description here

  1. Enforce “Your Seat” on unique values. The “enforce unique values” feature prevents users from duplicating data.

enter image description here

When user is trying to create duplicate data (the Table-Seat has already be selected), the error message will display and the item cannot be created successfully.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.