How to make un-editable only when editing, and not while adding?

[Bhadurudeen]

It would be a common practice in many scenarios, that a user should not be able to edit a (Employee-Name-)field while editing a record/row, and he should be able to edit(=add) a (Employee-Name-)field, while adding a new record.

But in Appsheet, when I change the (name)field to editable in the data, that field becomes editable in the form, where I don't want the user to edit it, during editing. 
If I make it un-editable, I am unable to add the name in a 'add new employee' form.

How to handle this situation?
(I want to achieve this on separate edit, add-new forms, not on edit-in-place forms.)

[TeeSee1]

https://www.googlecloudcommunity.com/gc/AppSheet-Q-A/Different-view-for-add-vs-edit/m-p/331552

[AleksiAlkio · Accepted solution]

Use NOT(IN([KeyColumn],Tablename[KeyColumn])) with the Editable?. It allows you to edit the record when it's not saved to datasource yet = adding new record.