Ch. 5

Question 1

Commands that modify data are called ________.

Answer 1

data manipulation language

Question 2

What command adds new rose to a table; can include a subquery to copy rows from an existing table?

Answer 2

INSERT

Question 3

What command adds data to, or modifies data in, existing rows?

Answer 3

UPDATE

Question 4

What command removes rows from a table?

Answer 4

DELETE

Question 5

What command saves changed data in a table permanently?

Answer 5

COMMIT

Question 6

What command allows “undoing” uncommitted changes to data?

Answer 6

ROLLBACK

Question 7

What command enables setting markers in a transaction?

Answer 7

SAVEPOINT

Question 8

What command prevents other users from making changes to a table?

Answer 8

LOCK TABLE

Question 9

What command creates a shared lock on a table to prevent another user from making changes to data in specified columns?

Answer 9

SELECT …

FOR UPDATE

Question 10

A _______ ________ in an SQL command instructs Oracle 11g to substitute a value in place of the variable at the time the command is actually executed.

Answer 10

Substitution Variable

Question 11

All ______ commands you execute remain in a transaction queue until you save the actions permanently or undo the actions.

Answer 11

DML

Question 12

A ______ is a term used to describe DML statements representing data actions that should logically be performed together.

Answer 12

transaction

Question 13

Which of the following is a correct statement?

a. A commit is issued implicitly when a user exits SQL developer or SQL*Plus.
b. A commit is issued implicitly when a DDL command is executed.
c. A commit is issued automatically when a DML command is executed.
d. All of the above are correct.
e. Both a and b are correct
f. Both a and c are correct

Answer 13

e. Both a and b are correct

Question 14

Which of the following is a valid SQL statement?

a. SELECT * WHERE amid = ‘J100’ FOR UPDATE;
b. INSERT INTO homework10 VALUES (SELECT * FROM acctmanager);
c. DELETE amid FROM acctmanager;
d. rollback;
e. all of the above

Answer 14

d. rollback;

Question 15

Which of the following commands can be used to add rows to a table?

a. INSERT INTO
b. ALTER TABLE ADD
c. UPDATE
d. SELECT ….. FOR UPDATE

Answer 15

a. INSERT INTO

Question 16

Which of the following statements deletes all rows in the HOMEWORK10 table?

a. DELETE * FROM homework10;
b. DELETE . FROM homework10;
c. DELETE FROM homework10;
d. DELETE FROM homework10 WHERE amid = (*);
e. Both c and d delete all rows in the HOMEWORK10 table.

Answer 16

c. DELETE FROM homework10;

Question 17

Which of the following statements places a shared lock on at least a portion of a table named HOMEWORK10?

a. SELECT * FROM homework10 WHERE col2 is NULL FOR UPDATE;
b. INSERT INTO homework10 (col1, col2, col3) VALUES (‘A’, ‘B’, ‘C’);
c. UPDATE homework10 SET col3 = NULL WHERE col1 = ‘A’;
d. UPDATE homework10 SEL col3 = LOWER (col3) WHERE col1= ‘A’;
e. all of the above

Answer 17

a. SELECT * FROM homework10 WHERE col2 is NULL FOR UPDATE;

Question 18

Which of the following symbols designates a substitution variable?

a. &
b. $
c. #
d. _

Answer 18

a. &

Question 19

Which of the following input values results in a successful INSERT of O’hara?

a. ‘O^hara’
b. ‘O’‘hara’ (two single quotes following the O)
c. ‘O”para’ ( a double quote following the O)
d. Data values can’t contain quotes

Answer 19

b. ‘O’‘hara’ (two single quotes following the O)

Question 20

Which of the following commands locks the HOMEWORK10 table in EXCLUSIVE mode?

a. LOCK TABLE homework10 EXCLUSIVELY;
b. LOCK TABLE homework10 IN EXCLUSIVE MODE;
c. LOCK TABLE homework10 TO OTHERS USERS;
d. LOCK homework10 IN EXCLUSIVE MODE;
e. Both b and d lock the table in EXCLUSIVE mode.

Answer 20

b. LOCK TABLE homework10 IN EXCLUSIVE MODE;

Question 21

You issue the following command: INSERT INTO homework10 (col1, col2, col3) VALUES (‘A’, NULL, ‘C’). The command will fail if which of the following statements is true?

a. Col1 has a PRIMARY KEY constraint enabled
b. Col2 has a UNIQUE constraint enabled.
c. COL3 is defined as a DATE column
d. None of the above would cause the command to fail.

Answer 21

d. None of the above would cause the command to fail.

Question 22

Which of the following releases a lock currently held by a user on the HOMEWORK10 table?

a. A COMMIT command is issued.
b. A DDL command is issued to end a transaction.
c. The user exits the system
d. A ROLLBACK command is issued.
e. all of the above
f. none of the above.

Answer 22

e. all of the above

Question 23

Assume you have added eight new orders to the ORDERS table. Which of the following is true?

a. Other users can view the new orders as soon as you execute the INSERT INTO command.
b. Other users can view the new orders as soon as you issue a ROLLBACK command.
c. Other users can view the new orders as soon as you exit the system or execute a COMMIT command.
d. Other users can view the new orders only if they place an exclusive lock on the table.

Answer 23

a. Other users can view the new orders as soon as you execute the INSERT INTO command.

Question 24

How many rows can be added to a table by executing the INSERT INTO ….VALUES COMMAND?

a. 1
b. 2
c. 3
d. unlimited

Answer 24

d. unlimited

Question 25

You accidentally deleted all the orders in the ORDERS table. How can the error be corrected after a COMMIT command has been issued?

a. ROLLBACK;
b. ROLLBACK COMMIT;
c. REGENERATE RECORDS orders;
d. None of the above restores the deleted orders.

Answer 25

d. None of the above restores the deleted orders.

Question 26

A rollback occurs automatically when:

a. A DDL command is executed
b. A DML command is executed
c. The user exits the system
d. none of the above

Answer 26

d. none of the above