Background information
You save your database diagram when you are ready to update the database to match your database diagram. However, if other users have updated the database since you opened your database diagram, their changes might affect your database diagram and vice versa. In such cases, saving your database diagram will automatically:
Saving your database diagram will reconcile the database with your database diagram by overwriting other usersÆ changes so that the database will match your database diagram.
Reconcile your database diagram with a modified database
If you have not previously saved your database diagram, type a name for the database diagram in the Save As dialog box and choose OK.
Note If your database diagram contains tables and columns that were deleted in the database, only their definitions are recreated in the database when you save your database diagram. This process does not restore any data that existed in these objects before their deletion.