Rules for Performing DML Operations on a View

• DML operation on simple view
• Cannot remove or modify a row if the view contains the following:
  - Group function
  - A GROUP BY clause
  - The DISTINCT keyword
  - The pseudocolumn ROWNUM keyword
  - columns defined by expressions (only modify)
  
• Cannot add data through a view if the view includes
  - Group function
  - A GROUP BY clause
  - The DISTINCT keyword
  - The pseudocolumn ROWNUM keyword
  - columns defined by expressions
  - NOT NULL columns in the base tables that are not selected by the view