Views

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

    create view v as   query expression   
   

   where query expression is any legal query expression.

   The view created is given the name v.

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

    create view all-customer as
   
   		 		 (select bname, cname
   
   		 		 from depositor, account
   
   		 		 where depositor.account# = account.account#)
   
   		 		 union
   
   		 		 (select bname, cname
   
   		 		 from borrower, loan
   
   		 		 where borrower.loan# = loan.loan#)
   
   

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

    select cname
   
   		 from all-customer
   
   		 where bname=``SFU''