Formula to know if parent has a child

[Marc_Torra]

I have a field called "Child_of" that links the child with the parent, both located on the same table.

Since Airtable does not offer backlinking to the same table, I need a formula to know if the parent has a child. I do not need the backlink to be added to the parent record, such as through an automation. I just need to know if that parent has a child, in which case the formula could return the value 1. Counting the number of children would also work, returning the number of children in the parent record.

I wonder if anyone could help me with that?

Many thanks, 🙏 

[Shannon_Bradley]

So if I understand correctly, Table A is the Parent information, with a field for Child.

Table B links to the parent and you also want it to show if that linked Parent has a child.

I believe a Lookup field might be easiest? If there is a value it will populate, if there isn't it will just be blank.

Something like this. I have Actors linked already, and here I can have it tell me if they have an associated Agency or not. Hope this helps!

[Marc_Torra]

Thanks Shannon but it will not work because a lookup only tells me if the record has a parent not if the parent has a child. Same with Rollup and Count.

See in the attached screenshot how I need the first record "Solar panel" to show that it has children, not the two children to show that they have ·"Solar panel" as their parent.

[Shannon_Bradley]

Oh I see the problem, it doesn't work the same when linking within the same table as it does between tables. Dang. I will play around, in the meantime hopefully a smarter person has an answer!

[TheTimeSavingCo]

You can't do this with a formula I think, and will need to use a script for it