Download Chapter 7 Review Questions (Word)

Database Processing, Ninth Edition
CHAPTER 7
Using SQL in Applications
True-False Questions
1.
When a surrogate key is used in the child table in an ID-dependent relationship
the relationship changes to a non-identifying relationship.
Answer: True
Level: moderate
Page: 229
2.
The SQL keyword CONSTRAINT is used to limit column values to specific values.
Answer: False
Level: easy
Page: 233
3.
An SQL virtual table is called a view.
Answer: True
Page: 235
Level: easy
4.
The SQL command CREATE USER VIEW is used to create a virtual table.
Answer: False
Level: moderate
Page: 235
5.
SQL views are constructed from SELECT statements.
Answer: True
Page: 235
Level: moderate
6.
According to the SQL-92, statements used to construct views cannot contain
the WHERE clause.
Answer: False
Level: moderate
Page: 235
7.
The SQL command SELECT is used to retrieve view instances.
Answer: True
Level: easy
Page: 235
8.
SQL views can be used to hide columns.
Answer: True
Page: 238
9.
Level: easy
SQL views can be use used to provide a level of indirection between
data processed by applications and the data actually stored in the database tables.
Answer: True
Level: moderate
Page: 238
7-1
Chapter 7 - Database Processing, Ninth Edition
10.
If the values in an SQL view are changeable through the view itself, the SQL command
UPDATE is used to change the values.
Answer: True
Level: moderate
Page: 243
11.
The values in an SQL view are always changeable through the view itself.
Answer: False
Level: moderate
Page: 243
12.
SQL views are updateable when the view is based on a single table
with no computed columns, and all non-null columns are present in the view.
Answer: True
Level: hard
Page: 243-244 [See Figure 7-13]
13.
SQL views are identical to ANSI/SPARC external schemas /user views.
Answer: False
Level: moderate
Page: 244
14.
A set of SQL statements stored in an application written in a standard programming
language is called embedded SQL.
Answer: True
Level: easy
Page: 245
15.
Because SQL statements are set-oriented, whereas programs are element-oriented, the results of
SQL statements used in programs are treated as files.
Answer: False
Level: moderate
Page: 245
16.
Because SQL statements are set-oriented, whereas programs are element-oriented, the results of
SQL statements used in programs are accessed using an SQL cursor.
Answer: True
Level: moderate
Page: 245
17.
A stored program that is attached to a table or view is called a stored procedure.
Answer: False
Level: moderate
Page: 246
18.
SQL triggers are used for validity checking, providing default values, and updating views.
Answer: True
Level: easy
Page: 246
19.
BEFORE UPDATE is an ANSI SQL trigger.
Answer: True
Page: 246
20.
Level: moderate
The Oracle DBMS supports the SQL trigger BEFORE.
Answer: True
Level: moderate
Page: 246
7-2
Chapter 7 - Database Processing, Ninth Edition
21.
The SQL Server DBMS supports the SQL trigger BEFORE.
Answer: False
Level: moderate
Page: 246
22.
SQL triggers can be used when the DBMS receives an insert request.
Answer: True
Level: easy
Page: 246
23.
When a trigger is fired, the DBMS makes the appropriate data available to the application code.
Answer: False
Level: hard
Page: 246
24.
SQL triggers are created using the SQL ADD TRIGGER statement.
Answer: False
Level: hard
Page: 247 [See Figure 7-14]
25.
To add a single initial value to a column, you would use the SQL DEFAULT constraint
with the CREATE TABLE command.
Answer: True
Level: hard
Page: 247
26.
To set a column value to an initial value that is selected according to some business logic,
you would use the SQL DEFAULT constraint with the CREATE TABLE command.
Answer: False
Level: hard
Page: 247
27.
If the values in an SQL view are not changeable through the view itself, you may still be able
to update the view by using unique application logic. In this case, the specific logic is placed in
an INSTEAD OF trigger.
Answer: True
Level: hard
Page: 248
28.
If a trigger is being written to enforce referential integrity actions,
you cannot use an INSTEAD OF trigger.
Answer: False
Level: hard
Page: 251
29.
A stored program that is attached to the database is called a trigger.
Answer: False
Level: moderate
Page: 251
30.
Stored procedures have the advantage of greater security, decreased network traffic,
SQL optimized by the DBMS compiler, and code sharing.
Answer: True
Level: moderate
Page: 251-253
7-3
Chapter 7 - Database Processing, Ninth Edition
31.
Unlike application code, stored procedures are never distributed to the client computers.
Answer: True
Level: moderate
Page: 252
32.
Because SQL stored procedures allow and encourage code sharing among developers,
stored procedures give database application developers the advantages of less work,
standardized processing, and specialization among developers.
Answer: True
Level: moderate
Page: 252 [See Figure 7-19]
Multiple Choice Questions
33.
When a surrogate key is used in the child table in an ID-dependent relationship
a.)
the parent table becomes the holder of the foreign key for the relationship
b.)
the surrogate key is allowed to contain null values
c.)
the surrogate key is allowed to contain non-unique values
d.)
the relationship changes to a non-identifying relationship
e.)
All of the above.
Level: moderate
Page: 229
34.
Given the SQL statement
CREATE TABLE SALESREP(
SalesRepNo
int
RepName
char(35)
HireDate
date
CONSTRAINT
CONSTRAINT
NOT NULL,
NOT NULL,
NOT NULL,
SalesRepPK
PRIMARY KEY (SalesRepNo),
SalesRepAK1 UNIQUE (RepName)):
we know that
.
a.)
RepName is the primary key
b.)
RepName is a foreign key
c.)
RepName is a candidate key
d.)
RepName is a surrogate key
e.)
none of the above is true
Level: hard
Page: 229-234
7-4
.
Chapter 7 - Database Processing, Ninth Edition
35.
The SQL keyword used to limit column values to specific values is
a.)
CONSTRAINT
b.)
CHECK
c.)
NOT NULL
d.)
UNIQUE
e.)
UPDATE
.
Level: easy
Page: 233
36.
An SQL virtual table is called __________________ .
a.)
a CHECK constraint
b.)
a view
c.)
embedded SQL
d.)
a trigger
e.)
a stored procedure
Level: easy
Page: 235
37.
The SQL command used to create a virtual table is
a.)
CREATE VTABLE
b.)
CREATE VIEW
c.)
VTABLE
d.)
VIEW
e.)
NEWLOOK
.
Level: moderate
Page: 235
38.
SQL views are constructed from
a.)
CREATE statements
b.)
INSERT statements
c.)
UPDATE statements
d.)
SELECT statements
e.)
VIEW statements
.
Level: moderate
Page: 235
39.
According to the SQL-92, statements used to construct views cannot contain
a.)
the SELECT clause
b.)
the FROM clause
c.)
the WHERE clause
d.)
the ORDER BY clause
e.)
SQL view statements can use all of the listed clauses
Level: moderate
Page: 235
7-5
.
Chapter 7 - Database Processing, Ninth Edition
40.
Which SQL statement is used to retrieve view instances?
a.)
CREATE
b.)
DELETE
c.)
INSERT
d.)
SELECT
e.)
UPDATE
Level: easy
Page: 235
41.
SQL views are used
.
a.)
to hide columns
b.)
to show results of computed columns
c.)
to hide complicated DQL statements
d.)
to provide a level of indirection between data processed by applications
and the data actually stored in the database tables
e.)
SQL views are used for all of the above
Level: easy
Page: 238
42.
If the values in an SQL view are changeable through the view itself, which SQL statement
is used to change the values?
a.)
CREATE
b.)
DELETE
c.)
INSERT
d.)
SELECT
e.)
UPDATE
Level: moderate
Page: 243
43.
When are the values in an SQL view changeable through the view itself?
a)
always
b.)
not always, but the rules to determine modification status are simple
c.)
not always, and the rules to determine modification status are complicated
d.)
not always, and the rules to determine modification status are DBMS-dependent
e.)
c and d
Level: moderate
Page: 243
7-6
Chapter 7 - Database Processing, Ninth Edition
44.
SQL views are always updateable when
.
a.)
the view is based on a single table with no computed columns,
and all non-null columns are present in the view
b.)
the view is based on any number of tables, with or without computed columns,
and the INSTEAD OF trigger is defined for the view
c.)
the view is based on multiple tables, the update is being done on the most subordinate
table, and the rows of that table can be uniquely identified
d.)
a and b
e.)
a, b and c
Level: hard
Page: 243-244 [See Figure 7-13]
45.
How do SQL views compare to ANSI/SPARC external schemas /user views?
a.)
they are identical
b.)
SQL views are a subset of ANSI/SPARC user views
c.)
ANSI/SPARC user views are a subset of SQL views
d.)
they are completely different, with an unfortunate similarity in their names
e.)
either b or c is correct depending on the particular database
Level: moderate
Page: 244
46.
A set of SQL statements stored in an application written in a standard programming
language is called __________________ .
a.)
a CHECK constraint
b.)
a view
c.)
embedded SQL
d.)
a trigger
e.)
a stored procedure
Level: easy
Page: 245
47.
Because SQL statements are set-oriented, whereas programs are element-oriented, the results of
SQL statements used in programs are treated as __________________ .
a.)
tables
b.)
columns
c.)
rows
d.)
files
e.)
pseudofiles
Level: moderate
Page: 245
7-7
Chapter 7 - Database Processing, Ninth Edition
48.
Because SQL statements are set-oriented, whereas programs are element-oriented, the results of
SQL statements used in programs are accessed using
.
a.)
standard programming tools
b.)
custom written programming tools
c.)
an SQL cursor
d.)
an SQL trigger
e.)
an SQL stored procedure
Level: moderate
Page: 245
49.
A stored program that is attached to a table or view is called __________________ .
a.)
a CHECK constraint
b.)
a view
c.)
embedded SQL
d.)
a trigger
e.)
a stored procedure
Level: easy
Page: 246
50.
SQL triggers are used for
a.)
validity checking
b.)
providing default values
c.)
updating views
d.)
a and b
e.)
a, b and c
.
Level: easy
Page: 246
51.
Which of the following is not an ANSI SQL trigger?
a.)
BEFORE UPDATE
b.)
INSTEAD OF UPDATE
c.)
BEFORE INSERT
d.)
INSTEAD OF CONSTRAINT
e.)
AFTER DELETE
Level: hard
Page: 246
7-8
Chapter 7 - Database Processing, Ninth Edition
52.
Which of the following is an SQL trigger Oracle supports?
a.)
BEFORE
b.)
INSTEAD OF
c.)
AFTER
d.)
b and c only
e.)
a, b and c
Level: moderate
Page: 246
53.
Which of the following is an SQL trigger Microsoft SQL Server supports?
a.)
BEFORE
b.)
INSTEAD OF
c.)
AFTER
d.)
b and c only
e.)
a, b and c
Level: moderate
Page: 246
54.
SQL triggers can be used when the DBMS receives a ____________request.
a.)
insert
b.)
update
c.)
delete
d.)
a and b
e.)
a, b and c
Level: easy
Page: 246
55.
When a trigger is fired, the DBMS makes the appropriate data available to
a.)
the SQL interpreter
b.)
the application code
c.)
the embedded SQL code
d.)
the trigger code
e.)
the stored procedure code
Level: easy
Page: 246
56.
SQL triggers are created using
.
a.)
the SQL CREATE TRIGGER statement
b.)
the SQL ADD TRIGGER statement
c.)
the SQL TRIGGER statement
d.)
the SQL ADD CONSTRAINT TRIGGER statement
e.)
the SQL CONSTRAINT TRIGGER statement
Level: hard
Page: 247 [See Figure 7-14]
7-9
.
Chapter 7 - Database Processing, Ninth Edition
57.
To add a single initial value to a column, you would use:
a.)
the SQL DEFAULT constraint with the CREATE TABLE command.
b.)
an SQL view.
c.)
embedded SQL.
d.)
an SQL trigger.
e.)
an SQL stored procedure.
Level: moderate
Page: 247
58.
To set a column value to an initial value that is selected according to some business logic,
you would use:
a.)
the SQL DEFAULT constraint with the CREATE TABLE command.
b.)
an SQL view.
c.)
embedded SQL.
d.)
an SQL trigger.
e.)
an SQL stored procedure.
Level: moderate
Page: 247
59.
If the values in an SQL view are not changeable through the view itself, you may still be able
to update the view by using unique application logic. In this case, the specific logic is placed in
a.)
a BEFORE trigger
b.)
an INSTEAD OF trigger
c.)
an AFTER trigger
d.)
depending on the specific logic, either a or b can be used
e.)
depending on the specific logic, any of a, b or c can be used
Level: hard
Page: 248
60.
If a trigger is being written to enforce referential integrity actions, you cannot use
.
a.)
a BEFORE trigger
b.)
an INSTEAD OF trigger
c.)
an AFTER trigger
d.)
depending on the specific referential integrity action, either b or c may be disallowed
e.)
depending on the specific referential integrity action, any of a, b or c may be disallowed
Level: hard
Page: 250
7 - 10
.
Chapter 7 - Database Processing, Ninth Edition
61.
A stored program that is attached to the database is called __________________ .
a.)
a CHECK constraint
b.)
a view
c.)
embedded SQL
d.)
a trigger
e.)
a stored procedure
Level: easy
Page: 251
62.
Stored procedures have the advantage of
a.)
greater security
b.)
decreased network traffic
c.)
SQL optimized by the DBMS compiler
d.)
code sharing
e.)
All of the above.
.
Level: easy
Page: 251-253 [See Figure 7-19]
63.
Unlike application code, stored procedures are never distributed to _______________ .
a.)
the DBMS
b.)
the client computers
c.)
the network servers
d.)
the database servers
e.)
All of the above.
Level: moderate
Page: 251
64.
Because SQL stored procedures allow and encourage code sharing among developers, stored
procedures give database application developers the advantages of
.
a.)
less work
b.)
standardized processing
c.)
specialization among developers
d.)
a and b
e.)
a, b and c
Level: moderate
Page: 252 [See Figure 7-19]
7 - 11
Chapter 7 - Database Processing, Ninth Edition
Fill in the Blank Questions
65.
When a surrogate key is used in the child table in an ID-dependent relationship
the relationship changes to a(n) non-identifying relationship .
Level: moderate
Page: 229
66.
The SQL keyword
Level: easy
Page: 233
CHECK is used to limit column values to specific values.
67.
An SQL virtual table is called a
Level: easy
Page: 235
68.
The SQL command
Level: easy
Page: 235
view .
CREATE VIEW is used to create a virtual table.
69.
SQL views are constructed from
Level: moderate
Page: 235
SELECT
statements.
70.
According to the SQL-92, statements used to construct views cannot contain
the ORDER BY clause.
Level: moderate
Page: 235
71.
The SQL command
Level: easy
Page: 235
SELECT
is used to retrieve view instances.
72.
SQL views can be used to hide table columns
Level: easy
Page: 238
.
73.
If the values in an SQL view are changeable through the view itself,
the SQL command UPDATE is used to change the values.
Level: moderate
Page: 243
74.
The values in an SQL view are not always changeable through
Level: moderate
Page: 244
7 - 12
the view itself
.
Chapter 7 - Database Processing, Ninth Edition
75.
When an SQL view is based on a single table with no computed columns, and all
non-null columns are present in the view, then the view is
updateable .
Level: moderate
Page: 243-244 [See Figure 7-13]
76.
SQL views are
Level: moderate
Page: 244
a subset of
ANSI/SPARC external schemas /user views.
77.
A set of SQL statements stored in an application written in a standard programming
language is called embedded SQL .
Level: easy
Page: 244
78.
Because SQL statements are set-oriented, whereas programs are element-oriented, the results of
SQL statements used in programs are treated as pseudofiles .
Level: moderate
Page: 245
79.
Because SQL statements are set-oriented, whereas programs are element-oriented, the results of
SQL statements used in programs are accessed using a(n)
SQL cursor .
Level: moderate
Page: 245
80.
A stored program that is attached to a table or view is called a(n)
Level: easy
Page: 246
SQL trigger
.
81.
SQL triggers use the ANSI SQL keywords BEFORE , INSTEAD OF , and AFTER .
Level: moderate
Page: 246
82.
SQL triggers can be used with SQL operations
Level: moderate
Page: 246
INSERT
83.
The Oracle DBMS supports the SQL triggers BEFORE,
Level: moderate
Page: 246
84.
The SQL Server DBMS does not support the SQL trigger
Level: moderate
Page: 246
85.
SQL
Level: easy
Page: 246
triggers
,
UPDATE , and DELETE .
INSTEAD OF , and AFTER .
BEFORE
.
can be used when the DBMS receives an insert request.
7 - 13
Chapter 7 - Database Processing, Ninth Edition
86.
When a trigger is fired, the DBMS makes the appropriate data available to
Level: hard
Page: 246
87.
SQL triggers are created using the SQL
Level: hard
Page: 246 [See Figure 7-14]
CREATE TRIGGER
the trigger code
statement.
88.
To add a single initial value to a column, you would use the SQL
Level: hard
Page: 246
DEFAULT constraint .
89.
To set a column value to an initial value that is selected according to some business logic,
you would use an SQL trigger
.
Level: moderate
Page: 246
90.
If the values in an SQL view are not changeable through the view itself, you may still be able
to update the view by using unique application logic. In this case, the specific logic is placed in
an INSTEAD OF
trigger.
Level: hard
Page: 248
91.
If a trigger is being written to enforce referential integrity actions,
you cannot use an
AFTER trigger.
Level: hard
Page: 250
92.
A stored program that is attached to the database is called a
Level: moderate
Page: 251
93.
In terms of application security, stored procedures are
Level: moderate
Page: 251-253
94.
Unlike application code, stored procedures are
Level: moderate
Page: 251
95.
stored procedure
.
more secure than application code.
never distributed
to the client computers.
SQL Stored procedures give database application developers the advantages of less work,
standardized processing, and specialization among developers because stored procedures
allow and encourage
code sharing among developers.
Level: moderate
Page: 252 [See Figure 7-19]
7 - 14
.
Chapter 7 - Database Processing, Ninth Edition
Essay Questions
Note to instructor:
The following database is should be provided to students as the basis for SQL
examples required by some of the questions that follow.
GENERAL SALES DATABASE:
SALESREP
SalesRepNo
654
734
345
434
CUSTOMER
CustNo CustName
9870
Winston
8590
Gonzales
7840
Harris
4870
Miles
96.
RepName
Jones
Smith
Chen
Johnson
Balance
500
350
800
100
HireDate
01/02/1999
02/03/2000
01/25/1998
11/23/1998
SalesRepNo
345
434
654
345
What is an SQL view, and what is it used for? Include an example based on the CUSTOMER
table of the General Sales Database.
An SQL view is a virtual table constructed from database tables or other views. It is based on the
SQL CREATE VIEW command and uses the SQL SELECT statement to construct the view.
However, the ORDER BY clause cannot be used when creating a view. For example:
CREATE VIEW CustomerNameOnly AS
SELECT CustName
FROM CUSTOMER;
A view may be used to (1) hide columns or rows, (2) show the results of computed columns, (3)
hide complicated SQL statements such as joins, and (4) provide a level of indirection between the
data processed by applications and the actual table data.
97.
Compare SQL views and the ANSI/SPARC external schema/user view.
An SQL view is a virtual table constructed from database tables or other views. The
ANSI/SPARC external schema/user view is a particular view of a portion of the database as seen
by an end user through a form in an application. While an SQL view is based on a single
SELECT statement, the user view seen on the form may be based on the results from more than
one SELECT statement. Therefore, while the two are not the same, we can consider that the SQL
view is a subset of the ANSI/SPARC external schema / user view.
7 - 15
Chapter 7 - Database Processing, Ninth Edition
98.
What is embedded SQL, and what considerations are necessary when using it in an application?
Embedded SQL are SQL statements used, or embedded, in program code, triggers or stored
procedures. Applications are typically written in program code, using a programming language.
There are two problems that arise. First, the results of SQL statements must be assigned to
programming language variables. DBMS products typically provide the means of doing this.
Second, SQL is set-oriented and SQL results use tables or sets of rows, whereas application
programming languages are element- or row-oriented. This is resolved by treating SQL results
as pseudo-files. A cursor is then used to move through the pseudofile one row at a time.
99.
What are SQL triggers and how are they used?
An SQL trigger is a stored program that is attached to a table or view. The trigger is invoked by
the DBMS whenever an insert, update or delete request is made on the table or view with the
trigger. There are three commonly used triggers: BEFORE, INSTEAD OF, and AFTER (MS SQL
server does not support BEFORE). This creates a set of nine possible trigger types: BEFORE +
[INSERT or UPDATE or DELETE], INSTEAD OF + [INSERT or UPDATE or DELETE], and
AFTER + [INSERT or UPDATE or DELETE]. Triggers are used (among other things) for (1)
validity checking, (2) providing default values, (3) updating views, and (4) enforcing referential
integrity actions.
100.
What are SQL stored procedures and how are they used?
An SQL stored procedure is a stored program that is attached to a database, instead of just a
table or view. Stored procedures can receive input parameters and return results. They can be
executed by any process that has permission with the database to use stored procedure. They are
typically used by (1) database administrators to do common administrative tasks, and (2)
database applications.
7 - 16