Action to update a row column when a row is selected by a checkbox in any row

[gougou]

I want to create an action that updates a row column (selection flag) when a row is selected in a view or when a checkbox is checked, but I don't know how to do it.
Please tell me how to do this.

[JPAlpano]

It's unclear what you are trying to accomplish.

Is the row being selected while.on a table/deck view?  Is the checkbox being referred to the multi-select indicator when rows are tapped and held (whole on a table/deck view)?

[gougou]

 Here is what we would like to do.

  https://www.googlecloudcommunity.com/gc/AppSheet-Q-A/I-want-to-create-a-CSV-file-of-arbitrarily-sele...

I would like to create a new csv file in the xlsx template for records that have multiple selections in the checkboxes in the parent record list view for records in a parent-child relationship.

To accomplish this, I would like to set up a column in the parent table for the selection flag (y/n), determine if the checkbox is checked in that column, and output only the records that are checked.

I would like to update the selection flag in the action when the checkbox is checked or unchecked.

Please let me know if there is a specific way to accomplish this.