Views Quiz - Feedback

You achieved a score of 3.00 out of 3.00.
Your answers, as well as our explanations, are shown below.

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Question 1
Consider the following schema: 
  Book(ISBN, title, year) // ISBN and title cannot be NULL
  Author(ISBN, name) // ISBN and name cannot be NULL
and the following view definition over this schema: 
  Create View V as
    Select Book.ISBN, count(*)
    From Book, Author
    Where Book.ISBN = Author.ISBN
    And Author.name Like 'A%'
    And Book.year > 2000
    Group By Book.ISBN
This view is not updatable according to the SQL standard, for a number of reasons. Which of the following is a valid reason for the view being non-updatable according to the standard?
Your answer Score Choice explanation
Two tables in FROM clause 1.00 Updatable views must have only one table in their top-level FROM clause.
Total 1.00 / 1.00
Question 2
Suppose a table T(A,B,C) has the following tuples: (1,1,3), (1,2,3), (2,1,4), (2,3,5), (2,4,1), (3,2,4), and (3,3,6). Consider the following view definition: 
   Create View V as
     Select A+B as D, C
     From T

Consider the following query over view V: 

   Select D, sum(C)
   From V
   Group By D
   Having Count(*) <> 1
Which of the following tuples is in the query result?
Your answer Score Choice explanation
(6,7) 1.00
Total 1.00 / 1.00
Question 3
Consider the following base tables. Capitalized attributes are primary keys. All non-key attributes are permitted to be NULL. 
   MovieStar(NAME, address, gender, birthdate)
   MovieExecutive(LICENSE#, name, address, netWorth)
   Studio(NAME, address, presidentLicense#)
Each of the choices describes, in English, a view that could be created with a query on these tables. Which one can be written as a SQL view that is updatable according to the SQL standard?
Your answer Score Choice explanation
A view "RichExecNums" containing the license number and net worth of all executives with a net worth of at least $10,000,000. 1.00 Although name and address are omitted from the view, they are permitted to be NULL.
Total 1.00 / 1.00