About the FROM Clause of an Updatable View

In a CREATE VIEW statement, for a view to be updatable, the FROM clause must follow these rules:

A view defined as using a derived table in the FROM clause is updatable as long as the derived table is selecting from a single table. The SELECT statement of the derived table must follow the same rules as rules as the rules for the SELECT of an updatable view (see About the SELECT List of an Updatable View).