The Set Column Values action allows you to change another column's values.

The Set Column Values action can be used as an action in the components of your app (like Buttons, Collections, and much more), or it can be triggered along with other actions as part of a Workflow.
Setting up the Set Column Values Action
In the Layout Editor
Click on the plus (+) sign in the Components panel and select the Component you want to trigger the action.
In the General tab on the right side of the Layout Editor, navigate to the Actions section and select Set column values.
Select the icon and descriptive text to use in your app.
Set the columns for which you’d like the value to be changed. You can fill in a custom static value, or use the value from a column in your data.
You can also leave any of the columns blank if you don’t want to change the values in that column.
You can optionally add Conditions for certain criteria to be met before a user can trigger this action.
In the Workflow Editor
Select the + New Workflow button. If you have existing actions, click on the plus (+) sign in the left panel.
Select the data source for your action.
Configure your first action by clicking the first step in the workflow. You can also add conditions to your actions, if needed.
To add new actions to the flow, hover just underneath an action and click the plus button. In this way you can add the Set Column Values action as just one step in a larger workflow.
Check the Introduction to Actions page for a full list of components that can be used to trigger actions.