Updating views on multiple tables
I think most databases are happy to update views that only involve a single table. But when you involve multiple tables, you have to provide a rule of some sort to tell the DBMS what to do when it can’t necessarily figure it out. Apparently Oracle will try to do an update on multiple tables, but the update will fail if there are issues. But as of Oracle v7.3, you can update views on multiple tables by using INSTEAD OF triggers.