Đề thi trắc nghiệm cơ sở dữ liệu trường Cao Thắng- phần 5 ppt

Which of the following statements will return the names of the products with Product ID 10, 11, or 42?. a SELECT ProductName FROM products WHERE ProductID IN 10,11,42 b SELECT ProductNam

20 Which of the following statements contains an error?

(a) SELECT * FROM emp WHERE empid = 493945;

(b) SELECT empid FROM emp WHERE empid= 493945;

(c) SELECT empid FROM emp;

(d) SELECT empid WHERE empid = 56949 AND lastname = 'SMITH';

21 Which of the following statements will return the names of the products with Product ID 10,

11, or 42?

(a) SELECT ProductName FROM products WHERE ProductID IN (10,11,42)

(b) SELECT ProductName FROM products WHERE ProductID IN 10

OR 11 OR 42

(c) SELECT ProductName FROM products WHERE ProductID = (10,11,42)

(d) SELECT ProductName FROM products WHERE ProductID IS (10,11,42)

(e) None of the above

22 Which of the following commands will return the list of

product names sorted in ascending

alphabetic order?

(a) SELECT ProductName FROM products ORDER BY ProductName DESC

(b) SELECT ProductName FROM products ORDER BY ProductName ASC

(c) SELECT ProductName FROM products SORTED BY

ProductName ASC

(d) SELECT ProductName FROM products SORTED BY

ProductName DESC

(e) None of the above

23 Which of the following will return a list of every product ID currently listed in the

order_details table where each product ID is listed only once? (a) SELECT DISTINCT ProductID FROM order_details

(b) SELECT ProductID FROM order_details ONLY ONCE

(c) SELECT ProductID FROM order_details

(d) SELECT UNIQUE ProductID FROM order_details

(e) None of the above

24 In the instance of the relation R(A,O,T,V,U) shown below, which of the following functional

dependencies hold ?

25 Which of the following statements contains an error?

(a) SELECT cid, sum (qty) from orders group by cid having

sum(dollars) > 2000;

(b) SELECT aid, avg (qty) from orders group by aid;

(c) SELECT cid, sum (dollars) from orders;

(d) SELECT count (*) from orders;

26 Which code lists employees by descending order of salary (a) SELECT * FROM EMPLOYEES SORT BY SALARY DESCENDING; (b) SELECT * FROM EMPLOYEES IN ORDER OF SALARY;

(c) SELECT * FROM EMPLOYEES ORDER BY SALARY DESC;

(d) SELECT * FROM EMPLOYEES ORDER BY SALARY;

27 In order to perform a join, which criteria must be true? (a) The two tables must have only one column exact same

columns

(b) The tables in the join need to have common rows

(c) The two tables must both have primary keys

(d) The two tables must have a common column

28 Consider the follow attributes and functional dependencies:

A B C

AB→ C

C → A

List all keys (not superkeys):

29 What will result from the following SQL Select statement? Giáo Trình Cơ Sở Dữ Liệu Trang 101

Biên soạn : Phan Tấn Quốc- Trường Cao Đẳng Kỹ Thuật Cao Thắng Select min(product_description)

from product_v;

(a) The minimum value of product_description will be displayed (b) An error message will be generated

(c) The first product description alphabetically in product_v will be shown

(d) none of the above

30 The following two SQL statements will produce the same

results:

Select last_name, first_name

from customer

where credit_limit > 99 and credit_limit < 10001;

Select last_name, first_name

from customer

where credit_limit between 100 and 10000; a.TRUE

b.FALSE