View Definition

1. A view is defined using the create view command:

   

   where <query expression> is any legal query expression.

   The view created is given the name .

2. To create a view all-customer of all branches and their customers:

   

3. Having defined a view, we can now use it to refer to the virtual relation it creates. View names can appear anywhere a relation name can.

4. We can now find all customers of the SFU branch by writing