How do I identify redundant data through a query?

Hi,

I’m currently using a google sheet which contains user input from a form, I want to identify repeating values in a column (ID numbers).
Additionally, I’m planning to compare the row index, higher value row index will be the repeated entry and I want to edit a column in the repeated row with the text " Repeated ".

Any help or suggestions on how to implement this? Or is there a way to do it without query?

Hi! Can you share some screenshots or a screen recording that shows the workflow to help us understand the use case better?

Hi, I currently do not have a workflow since its not implemented, But I’ll give an example.

An Employee is requesting for his leave or day-off, the employee cannot have 2 requests at once. Once HR of the company enters employee data for leave with employee ID, they cannot enter until the previous request is completed. So I just want to check if the ID is already present in the column when they are submit the ID - and then display a message or something to tell them its already there.

We have a sample app that validates if an entry is already present in the database before submitting it. Please fork it and let us know if it helps.