Adding a field to changeset

In addition to the changeset, is it possible to update a column? Something like

Yes, should be possible by using the map function on your changsetArray and the spread operator e.g.:

{{ => { return {...element , myProperty: newValue} } ) }}

This should return a new array of the original objects with myProperty appended to each object (or the value of myProperty is updated, if it already exists in the object)