Review II

17) Which data type should a database use to store negative numbers? a. INT b. BLOB c. CHAR d. DATETIME

a. INT

22) A NULL value represents _____ data. a. missing b. ignored c. relational d. primary

a. missing

19) When only one value exists in each cell, a table is known to be _____. a. normalized b. data independent c. relational d. structured

a. normalized

21) Evaluate the given data and determine the correct result from the statement. SELECT SUM(cost) + SUM(markup) FROM profit; a. 450, 35 b. 125, 200, 160 c. 485 d. 250, 35

c. 485

14) In a relational database model, which concept refers to a finite sequence of values that are derived from defined domains? a. Attribute b. Set c. Tuple d. Structure

c. Tuple

15) A database administrator creates a new relational database, and a primary key is assigned within a table to assist with governing data. What does the administrator accomplish with this structural rule? a. No missing values within a column in the table b. Unique naming of columns within the table c. Unique identification of individual rows in the table d. Cascade deletion of all related rows in the database

c. Unique identification of individual rows in the table

24) Which two rules apply to primary keys? a. Values can have duplicates and may not be NULL b. Values must be unique and can be NULL c. Values must be unique and may not be NULL d. Values can have duplicates and can be NULL

c. Values must be unique and may not be NULL

20) A relational database uses _____ to structure all data. a. queries b. columns c. tables d. cells

c. tables

25) In the Reservation table below, a room may be reserved several times, so the RoomNumber column is not unique. To ensure that a room can only be reserved by only one guest for the day, the minimal primary key consists of which columns? a. (RoomNumber, DateOfStay, Guest) b. (RoomNumber, ModeOfPayment) c. (RoomNumber, Guest, ModeOfPayment) d. (RoomNumber, DateOfStay)

d. (RoomNumber, DateOfStay)

16) What data type stores binary values? a. FLOAT b. INT c. POINT d. BLOB

d. BLOB

18) A _____ is a collection of values that are of the same type. a. table b. cell c. row d. column

d. column

23) A column, or group of columns, that serves as the unique identifier in a relational database table is called a/an _____. a. candidate key b. foreign key c. alternate key d. primary key

d. primary key