Quick tip please! How to extend a list

I have a table with a list of room names: column A = room name.
The unique room owner resides in column B.

So far so good. I would now like to define Column C so that each room contains a corresponding list of guest names, e.g. each cell contains a list. I assume each cell will be a list of names and that I can use a component with a pick-list of names that allows the room owner to add a guest name to the list.

Any tips on how to do this please? I am familiar with forms, choice components and relations but I have never had a component that can add to list. Do I need to work up a relation? I have never worked with arrays before… maybe this will be answer!

Thanks in advance for your time.

Hola @Simon_Hill

I would do it this way:

  1. set up a log sheet where room owner have all the room guests (guests should be a column as well). In that sheet you need to have either the room owner or the room ID

  2. on the room sheet, make a relation that matches either the room owner or room ID in the log tab.

  3. in the room sheet, create a joined list column against that relation and bring the guests to your room sheet. Now you can display that list.

I hope this helps.


Sorry I don’t follow this.

Either I have to add a list of rooms into a cell corresponding to a name in the user sheet. Or I have to add a list of names into a cell corresponding to a room in the rooms sheet. Either way, I need to be able to add to a list within a cell… the relation will not work without doing that.


If the length of the guest list for any given room is variable, then probably the best way to handle this is with a 2nd sheet (which is what @SantiagoPerez is suggesting).

In that sheet you have two columns:

  • Room ID
  • Guest ID

The sheet will have one row per guest/room combination.
To get a list of guests in any given room, create a multi-relation linking the room ID in this sheet back to the same room in your original sheet.
You can probably figure out the rest :slightly_smiling_face:


It took me a while… but I get it. Thanks so much!