Comparing two arrays and remove values that appear in both

[Phil_Miller]

Hi airtable!

I have a list (an array) of items in two columns. Each row represents two different lists (one in each column). I’d like to be able to compare the two columns and remove what is common in both. For example

Row 1:
Column 1: Apple, Orange, Pineapple, Kiwi
Column 2: Apple, Kiwi

Result: Column 3: Orange, Pineapple

Row 2:

Column 1: Banana, Orange, Grape, Kiwi, Pineapple, Passion Fruit
Column 2: Orange, Grape, Pineapple

Result: Column 3: Banana, Kiwi, Passion Fruit
etc.

The general functionality is to be able to compare (two or more arrays) and perform some kind of action.

Is this something that could be worked on?

Let me know if you’d like more details.

There are a few other posts here from people who have similar requests and ideas:

Removing specific values from arrays (this is mine in support)
Array intersect formula
Using Rollup to check on completed tasks?

[Jeremy_Oglesby]

Nope – that post was a #product-suggestions for Airtable. None of the stuff I posted up there can be done yet.

[Jason_Calaiaro]

+1 for this, I’m stuck on the same issue (and same use case).

[Oli_Steadman]

Here here I’d like to see this.

[Russell_Bishop1]

Need this so bad! Arrayunique is flawed outside of Rollups…

[Tom_Kerswill]

This is a really essential feature for me…

[Jon_Shay]

Me too, would be great to be able to have the inverse as well, eg: finding linked records that meet different criteria.

[Air_Table3]

You could create a table with both sets of data (including duplicates) then use the “Dedupe” app to remove the ones you don’t want.

[Simon_Forster]

I can’t believe this hasn’t been implemented yet - FOUR AND A HALF years later

[Jason_Sears1]

Yes, I’d like this too - Need an easy way to generate an email list that omits people who have already responded…

[Alexey_Gusev]

Difference between airtable and spreadsheet is that each airtable formula is array function itself, applied to a vertical column of data.
Like in other databases, similar types of data located in column, so variety of array functions can be used as native feature, without special formulas.

I have some tables containing 50k records and formula applied to rollup function which works quite fast, I mean it changed in realtime despite each of 50k values passes through loop comparing with other 50k list. It’s 2.5 billion operations. Of course, alghorhytm optimized and it uses less loop cycles.
But imagine Airtable has such “horizontal” formula an I put it to field. So it should count these 2.5*10^9 operations for each of 50k rows and do it in realtime. I don’t think it’s possible. At least for multi-user cloud service.