Limit Multiple Selection total

[DisraeliGears]

Hi there! I'm trying to design a base with a public facing form for camp registrations. I was planning to use multiple select as the camp selections field, so folks can sign up for Camp A, Camp C, and Camp D all through one form. 

Where I'm running into issues is designing an automation that disables selections when they reach a total. For ex. only 12 people can register for Camp A, so when 12 form submissions come in with that selected, it needs to be removed from the list of options. 

In a different setup, I've used lookups, views, and table links to create this utility, but that was date/time based, so I could use it as the primary field. I can't use multiple select as a primary though, so I'm a bit stuck. 

[ScottWorld]

Airtable's new interface forms allow you to specify limits for multi-select fields and linked record fields.

Unfortunately, this is not a feature that is available on the legacy form views, so if you're trying to do this on a form view, it is not possible.

It's worth noting that "specifying limits" is also a feature of Fillout's advanced forms for Airtable, which offers about 100 additional features for Airtable that Airtable's native forms don't offer.

[DisraeliGears]

Hi Scott!

I've played around the new interface form option, and the issue is that I don't need to limit the amount of options people can select, but rather I need to limit the amount of times an option can be selected. Chewing on it a bit more, it's a kind of inventory issue, I only have X amount of Option 1 before it's sold out. I can't quite figure out how to enforce that limitation. Some kind of formula or rollup that tabulates those selections, and then an automation changes the multiselect option to "Sold Out"? But automations don't modify fields (unless that's in the script section, which is too advanced for me)....

[ScottWorld]

You can limit people’s ability to choose a linked record based on a view.

So in your camps table, you can create a view that is filtered to only show you camps that still have space available in them.

Then, your linked record field can only select from the camps that are on that view.

I show how to do something similar — but not identical — on this Airtable podcast episode. 

[DisraeliGears]

Yep, I've done something similar to this using dates as a primary field and sorting by view. There's a few problems I'm running into implementing that solution, specifically that the linked record selector only displays the primary field. As single or multi selects can't be the primary field, that throws up a big listed of "unnamed fields". The other issue is that filtering views based on multiselect only gives me is/includes/empties filters, not greater than/less than numerical filters.

Just tried to get around this by using short text field with item names as the primary field (scrapping multiselect entirely) but then when you use the picker it gives you a huge list...

Thinking as I type, perhaps I make a multiselect with conditional linked fields for the available registrations. So they select Camp A and Camp C, and then the fields pop in with available registrations...

[ScottWorld]

Hmmm... it sounds like your Airtable database might not be setup in the most optimal way.

Instead of using multi-select fields, it sounds like you might be better off using linked record fields.

Also, for your primary field, if you're planning on using Airtable's forms, I would recommend using a formula field as your primary field that shows you all the information that you want to see.

Although if you're using Fillout's advanced Airtable forms for your forms, you can choose whichever fields you would like to display in your linked record picker, including attachment fields.

p.s. If you have a budget for your project and you’d like to hire an expert Airtable consultant to help you with any of this, please feel free to contact me through my website: Airtable consultant — ScottWorld 

[TheTimeSavingCo]

Hmm, you could try to do this with one linked field and view per camp?  If you've got a lot of camps this probably isn't tenable though

So you'd have a table for form submissions and a table for camp slots where each record represents one slot for that camp, and they'd be set up like this:


In "Slots", there's one view per camp, and the filter is the "Select" field is that camp, and that the linked field for that camp is empty:


In your form, you'd set the linked fields to only display based on the select field, and to limit each view respectively

And so your users would go to the form and select the camp they want, which shows the correct linked field:

And that linked field will only display records from the "Slots" table that aren't linked to any form submissions and have the correct "Camp" option.  So once all the slots you've created for that camp are taken, people can't sign up anymore, and you could put an explanation text in the form:

Link to base