I am wondering if it is possible to grey out already selected items in multiple choice or single choice. For example, when my client books appointment, I want to make each time slot available for only one client, if one time slot is already selected by previous client it will be showing not available or greyed out for next client.

Hi Nick,

Thanks for your inquiry

We are kindly letting you know that it is possible to implement using MySQL Mapping functionality.

Adding Select field you need to connect to that table using Select Option from Database . Please check
this link . Select the name/ option > Save.

Then go to Form Options > MySQL Mapping > Add Query > Select Delete > Connect. Here I am showing. Then select the same table ans add the condition clicking on the Plus button.

In the attached file I am showing how you can add the condition and generate the query.

Thanks and have a great day!