Discard Changes Made to Diagrams (Visual Database Tools)
You can discard changes in your database diagram that you do not want to save in the database.
To discard pending modifications
Close your database diagram or table design window.
A message prompts you to save your changes. Choose No.
Warning
If you have other open database diagrams or table design windows connected to the same database, close them without saving changes as well.
See Also
Other Resources
Work with Database Diagrams (Visual Database Tools)
Work with Tables in Database Diagram (Visual Database Tools)