Database
Programming with SQL Section 9 Quiz
(Answer all questions in this section)
1.
If you want to include subtotals and
grand totals for all columns mentioned in a GROUP BY clause, you should use
which of the following extensions to the GROUP BY
clause? Mark for Review
(1)
Points
HAVING
ROLLUP
CUBE (*)
GROUP BY ALL COLUMNS
2.
Examine the following statement:
SELECT
department_id, manager_id, job_id, SUM(salary)
FROM
employees
GROUP BY
GROUPING SETS((department_id, manager_id), (department_id, job_id))
What
data will this query generate?
Mark
for Review
(1)
Points
Sum of salaries for (department_id, job_id) and (department_id, manager_id) (*)
Sum of salaries for (department_id, job_id, manager_id)
Subtotals for (job_id, manager_id)
The statement will fail.
3.
Examine the following statement:
SELECT
department_id, manager_id, job_id, SUM(salary)
FROM
employees
GROUP BY
ROLLUP(department_id, manager_id)
What
extra data will this query generate?
Mark
for Review
(1)
Points
Subtotals for department_id, and grand totals for salary
Subtotals for department_id, job_id and grand totals for salary
Subtotals for department_id, job_id, manager_id and grand totals for salary
The statement will fail. (*)
4.
You use ROLLUP to: Mark
for Review
(1)
Points
produce subtotal values (*)
cross-tabulate values
produce a single result set
5.
CUBE will cross-reference the
columns listed in the ______ clause to create a superset of
groups. Mark for Review
(1)
Points
GROUP BY (*)
WHERE
SELECT
6.
CUBE can be applied to all aggregate
functions including AVG, SUM, MIN, MAX, and COUNT. True or False? Mark
for Review
(1)
Points
True (*)
False
7.
Which of the following are correct
SET operators? (choose two) Mark for
Review
(1)
Points
(Choose all correct answers)
MINUS, PLUS
UNION, MINUS (*)
UNION ALL, PLUS ALL
UNION ALL, INTERSECT (*)
8.
The ___________ operator returns all
rows from both tables, after eliminating duplicates. Mark for
Review
(1)
Points
UNION ALL
UNION (*)
MINUS
INTERSECT
9.
To control the order of rows
returned using SET operators, the ORDER BY clause is used ______ and is placed
in the _____ SELECT statement of the query. Mark for Review
(1)
Points
ONCE; LAST (*)
IN ALL; LAST
ONCE; FIRST
TWICE; FIRST
10.
If a select list contains both a column as well as a
group function then what clause is
required? Mark for Review
(1)
Points
HAVING clause
GROUP BY clause (*)
ORDER BY clause
JOIN clause
11.
Is the following statement correct?
SELECT
first_name, last_name, salary, department_id, COUNT(employee_id)
FROM
employees
WHERE
department_id = 50
GROUP BY
last_name, first_name, department_id;
Mark
for Review
(1)
Points
Yes
No, because the statement is missing salary in the GROUP BY clause (*)
Yes, because Oracle will correct any mistakes in the statement itself
No, beause you cannot have a WHERE-clause when you use group functions.
12.
What will the following SQL Statement do?
SELECT
job_id, COUNT(*)
FROM
employees
GROUP BY
job_id;
Mark
for Review
(1)
Points
Displays each job id and the number of people assigned to that job id (*)
Displays all the jobs with as many people as there are jobs
Displays only the number of job_ids
Displays all the employees and groups them by job
13.
The PLAYERS table contains these columns:
PLAYER_ID
NUMBER PK
PLAYER_NAME
VARCHAR2 (30)
TEAM_ID
NUMBER
HIRE_DATE
DATE
SALARY
NUMBER (8,2)
Which
clauses represent valid uses of aggregate functions? (Choose three.)
Mark
for Review
(1)
Points
(Choose all correct answers)
SELECT AVG(NVL(salary, 0)) (*)
GROUP BY MAX(salary)
ORDER BY AVG(salary) (*)
WHERE hire_date > AVG(hire_date)
HAVING MAX(salary) > 10000 (*)
14.
Evaluate this SELECT statement:
SELECT
MIN(hire_date), department_id
FROM
employees
GROUP BY
department_id;
Which
values are displayed?
Mark
for Review
(1)
Points
The hire dates in the EMPLOYEES table that contain NULL values
The latest hire date in the EMPLOYEES table
The earliest hire date in each department (*)
The earliest hire date in the EMPLOYEES table
15.
The EMPLOYEES table contains these columns:
ID_NUMBER
NUMBER Primary Key
NAME
VARCHAR2 (30)
DEPARTMENT_ID
NUMBER
SALARY
NUMBER (7,2)
HIRE_DATE
DATE
Evaluate
this SQL statement:
SELECT
id_number, name, department_id, SUM(salary)
FROM
employees
WHERE salary
> 25000
GROUP BY
department_id, id_number, name
ORDER BY
hire_date;
Why will
this statement cause an error?
Mark
for Review
(1)
Points
The HAVING clause is missing.
The SALARY column is NOT included in the GROUP BY clause.
The WHERE clause contains a syntax error.
The HIRE_DATE column is NOT included in the GROUP BY clause. (*)
1.
Which statement about group
functions is true? Mark
for Review
(1)
Points
Group functions can only be used in a SELECT list.
A query that includes a group function in the SELECT list must include a GROUP
BY clause.
Group functions ignore null values. (*)
Group functions can be used in a WHERE clause.
2.
What is the best explanation as to
why this SQL statement will NOT execute?
SELECT
department_id "Department", AVG (salary)"Average"
FROM
employees
GROUP BY
Department;
Mark
for Review
(1)
Points
The GROUP BY clause must have something to GROUP.
Salaries cannot be averaged as not all the numbers will divide evenly.
You cannot use a column alias in the GROUP BY clause. (*)
The department id is not listed in the departments table.
3.
The PRODUCTS table contains these
columns:
PROD_ID
NUMBER(4)
PROD_NAME
VARCHAR(20)
PROD_CAT
VARCHAR2(15)
PROD_PRICE
NUMBER(5)
PROD_QTY
NUMBER(4)
You need
to identify the minimum product price in each product category.
Which
statement could you use to accomplish this task?
Mark
for Review
(1)
Points
SELECT prod_price, MIN (prod_cat)
FROM
products
GROUP BY
prod_cat;
SELECT prod_cat, MIN (prod_price)
FROM
products
GROUP BY
prod_price;
SELECT prod_cat, MIN (prod_price)
FROM
products
GROUP BY
prod_cat;
(*)
SELECT MIN (prod_price), prod_cat
FROM
products
GROUP BY
MIN (prod_price), prod_cat;
4.
Evaluate this statement:
SELECT
department_id, AVG(salary)
FROM employees
WHERE
job_id <> 69879
GROUP BY
job_id, department_id
HAVING
AVG(salary) > 35000
ORDER BY
department_id;
Which
clauses restricts the result? Choose two.
Mark
for Review
(1)
Points
(Choose all correct answers)
GROUP BY job_id, department_id
WHERE job_id <> 69879 (*)
SELECT department_id, AVG(salary)
HAVING AVG(salary) > 35000 (*)
5.
The PRODUCTS table contains these
columns:
PRODUCT_ID
NUMBER(9) PK
CATEGORY_ID
VARCHAR2(10)
LOCATION_ID
NUMBER(9)
DESCRIPTION
VARCHAR2(30)
COST
NUMBER(7,2)
PRICE
NUMBER(7,2)
QUANTITY
NUMBER
You
display the total of the extended costs for each product category by location.
You need
to include only the products that have a price less than $25.00.
The
extended cost of each item equals the quantity value multiplied by the cost
value.
Which
SQL statement will display the desired result?
Mark
for Review
(1)
Points
SELECT SUM(cost * quantity) TOTAL
FROM
products
WHERE
price < 25.00;
SELECT category_id, SUM(cost * quantity) TOTAL,location_id
FROM
products
WHERE
price > 25.00
GROUP BY
category_id, location_id;
SELECT SUM(cost * quantity) TOTAL, location_id
FROM
products
WHERE
price < 25.00
GROUP BY
location_id;
SELECT category_id, SUM(cost * quantity) TOTAL, location_id
FROM
products
WHERE
price < 25.00
GROUP BY
category_id, location_id;
(*)
6.
Evaluate this SELECT statement:
SELECT
COUNT(employee_id), department_id
FROM
employees
GROUP BY
department_id;
You only
want to include employees who earn more than 15000.
Which
clause should you include in the SELECT statement?
Mark
for Review
(1)
Points
HAVING salary > 15000
HAVING SUM(salary) > 15000
WHERE salary > 15000 (*)
WHERE SUM(salary) > 15000
7.
You use GROUPING functions
to: Mark for Review
(1)
Points
Produce subtotal and cross-tabulated values
Identify the extra row values created by either a ROLLUP or CUBE operation (*)
Aggregate rows using SUM, MIN, MAX, and COUNT
8.
Examine the following statement:
SELECT
department_id, manager_id, job_id, SUM(salary)
FROM
employees
GROUP BY
GROUPING SETS((department_id, manager_id), (department_id, job_id))
What
data will this query generate?
Mark
for Review
(1)
Points
Sum of salaries for (department_id, job_id) and (department_id, manager_id) (*)
Sum of salaries for (department_id, job_id, manager_id)
Subtotals for (job_id, manager_id)
The statement will fail.
9.
CUBE will cross-reference the
columns listed in the ______ clause to create a superset of
groups. Mark for Review
(1)
Points
SELECT
GROUP BY (*)
WHERE
10.
You use ROLLUP to: Mark for Review
(1) Points
cross-tabulate values
produce subtotal values (*)
produce a single result set
11.
GROUPING SETS is another extension to the GROUP BY
clause and is used to specify multiple groupings of data but provide a single
result set. True or
False? Mark for Review
(1)
Points
True (*)
False
12.
If you want to include subtotals and grand totals for
all columns mentioned in a GROUP BY clause, you should use which of the
following extensions to the GROUP BY
clause? Mark for Review
(1)
Points
ROLLUP
GROUP BY ALL COLUMNS
HAVING
CUBE (*)
13.
Which of the following are correct SET operators?
(choose two) Mark for Review
(1)
Points
(Choose all correct answers)
UNION, MINUS (*)
UNION ALL, PLUS ALL
MINUS, PLUS
UNION ALL, INTERSECT (*)
14.
The difference between UNION and UNION ALL is
Mark for Review
(1)
Points
There is no difference; you get exactly the same result from both.
UNION ALL is more like a NATURAL JOIN.
UNION will remove duplicates; UNION ALL returns all rows from all queries
including the duplicates. (*)
UNION is a synomym for UNION ALL.
15.
When using SET operators, the names of the matching
columns must be identical in all of the SELECT statements used in the query.
True or False? Mark for Review
(1)
Points
True
False (*)
1.
How would you alter the following
query to list only employees where two or more employees have the same last
name?
SELECT
last_name, COUNT(employee_id)
FROM
EMPLOYEES
GROUP BY
last_name;
Mark
for Review
(1)
Points
SELECT last_name, COUNT(employee_id)
FROM
EMPLOYEES
WHERE
COUNT(*) > 1
GROUP BY
last_name
SELECT last_name, COUNT(last_name)
FROM
EMPLOYEES
GROUP BY
last_name
HAVING
COUNT(last_name) > 1;
(*)
SELECT last_name, COUNT(last_name)
FROM
EMPLOYEES
GROUP BY
last_name
EXISTS
COUNT(last_name) > 1;
SELECT employee_id, DISTINCT(last_name)
FROM
EMPLOYEES
GROUP BY
last_name
HAVING
last_name > 1;
2.
Which statement about the GROUP BY
clause is
true? Mark
for Review
(1)
Points
To exclude rows before dividing them into groups using the GROUP BY clause, you
should use a WHERE clause. (*)
You can use a column alias in a GROUP BY clause.
You must use the HAVING clause with the GROUP BY clause.
By default, rows are not sorted when a GROUP BY clause is used.
3.
The PRODUCTS table contains these
columns:
PRODUCT_ID
NUMBER(9) PK
CATEGORY_ID
VARCHAR2(10)
LOCATION_ID
NUMBER(9)
DESCRIPTION
VARCHAR2(30)
COST
NUMBER(7,2)
PRICE
NUMBER(7,2)
QUANTITY
NUMBER
You
display the total of the extended costs for each product category by location.
You need
to include only the products that have a price less than $25.00.
The
extended cost of each item equals the quantity value multiplied by the cost
value.
Which
SQL statement will display the desired result?
Mark
for Review
(1)
Points
SELECT SUM(cost * quantity) TOTAL, location_id
FROM
products
WHERE
price < 25.00
GROUP BY
location_id;
SELECT category_id, SUM(cost * quantity) TOTAL,location_id
FROM
products
WHERE
price > 25.00
GROUP BY
category_id, location_id;
SELECT category_id, SUM(cost * quantity) TOTAL, location_id
FROM
products
WHERE
price < 25.00
GROUP BY
category_id, location_id;
(*)
SELECT SUM(cost * quantity) TOTAL
FROM
products
WHERE
price < 25.00;
4.
Evaluate this SELECT statement:
SELECT
SUM(salary), department_id, manager_id
FROM
employees
GROUP BY
department_id, manager_id;
Which
SELECT clause allows you to restrict the rows returned, based on a group
function?
Mark
for Review
(1)
Points
HAVING salary > 100000
HAVING SUM(salary) > 100000 (*)
WHERE salary > 100000
WHERE SUM(salary) > 100000
5.
The PLAYERS and TEAMS tables contain
these columns:
PLAYERS
PLAYER_ID
NUMBER NOT NULL, PRIMARY KEY
LAST_NAME
VARCHAR2 (30) NOT NULL
FIRST_NAME
VARCHAR2 (25) NOT NULL
TEAM_ID
NUMBER
POSITION
VARCHAR2 (25)
TEAMS
TEAM_ID
NUMBER NOT NULL, PRIMARY KEY
TEAM_NAME
VARCHAR2 (25)
You need
to create a report that lists the names of each team with more than three goal
keepers.
Which
SELECT statement will produce the desired result?
Mark
for Review
(1)
Points
SELECT t.team_name, COUNT(p.player_id)
FROM
players p, teams t
ON
(p.team_id = t.team_id)
WHERE
UPPER(p.position) = 'GOAL KEEPER'
GROUP BY
t.team_name
HAVING
COUNT(p.player_id) > 3;
SELECT t.team_name, COUNT(p.player_id)
FROM
players p
JOIN
teams t ON (p.team_id = t.team_id)
WHERE
UPPER(p.position) = 'GOAL KEEPER'
GROUP BY
t.team_name
HAVING
COUNT(p.player_id) > 3;
(*)
SELECT t.team_name, COUNT(p.player_id)
FROM
players
JOIN
teams t ON (p.team_id = t.team_id)
WHERE
UPPER(p.position) = 'GOAL KEEPER'
HAVING
COUNT(p.player_id) > 3;
SELECT t.team_name, COUNT(p.player_id)
FROM
players p, teams t
ON
(p.team_id = t.team_id)
WHERE
UPPER(p.position) = 'GOAL KEEPER'
GROUP BY
t.team_name;
6.
Evaluate this statement:
SELECT
department_id, AVG(salary)
FROM
employees
WHERE
job_id <> 69879
GROUP BY
job_id, department_id
HAVING
AVG(salary) > 35000
ORDER BY
department_id;
Which
clauses restricts the result? Choose two.
Mark
for Review
(1)
Points
(Choose all correct answers)
WHERE job_id <> 69879 (*)
SELECT department_id, AVG(salary)
HAVING AVG(salary) > 35000 (*)
GROUP BY job_id, department_id
7.
Examine the following statement:
SELECT
department_id, manager_id, job_id, SUM(salary)
FROM
employees
GROUP BY
GROUPING SETS((department_id, manager_id), (department_id, job_id))
What
data will this query generate?
Mark
for Review
(1)
Points
Sum of salaries for (department_id, job_id) and (department_id, manager_id) (*)
Sum of salaries for (department_id, job_id, manager_id)
Subtotals for (job_id, manager_id)
The statement will fail.
8.
You use GROUPING functions to ______
database rows from tabulated
rows. Mark for Review
(1)
Points
COMPUTE
COUNT
DISTINGUISH (*)
CREATE
9.
Examine the following statement:
SELECT
department_id, manager_id, job_id, SUM(salary)
FROM
employees
GROUP BY
GROUPING SETS(.......);
Select
the correct GROUP BY GROUPING SETS clause from the following list:
Mark
for Review
(1)
Points
GROUP BY GROUPING SETS ((department_id, manager_id), (department_id, job_id),
(manager_id, job_id)) (*)
GROUP BY GROUPING SETS ((department_id, manager_id), (department_id,
SUM(salary), (manager_id, job_id))
GROUP BY GROUPING SETS (department_id, AVG(salary)), (department_id, job_id),
(department_id, manager_id)
GROUP BY GROUPING SETS (department_id, salary), (department_id, job_id),
(department_id, manager_id)
10.
CUBE can be applied to all aggregate functions
including AVG, SUM, MIN, MAX, and COUNT. True or False? Mark for Review
(1)
Points
True (*)
False
11.
GROUPING SETS is another extension to the GROUP BY
clause and is used to specify multiple groupings of data but provide a single
result set. True or
False? Mark for Review
(1)
Points
True (*)
False
12.
If you want to include subtotals and grand totals for
all columns mentioned in a GROUP BY clause, you should use which of the
following extensions to the GROUP BY
clause? Mark for Review
(1)
Points
HAVING
ROLLUP
CUBE (*)
GROUP BY ALL COLUMNS
13.
The ___________ operator returns all rows from both
tables, after eliminating duplicates. Mark for Review
(1)
Points
MINUS
UNION ALL
UNION (*)
INTERSECT
14.
MINUS will give you rows from the first query that are
not present in the second query. (True or
False?) Mark
for Review
(1)
Points
True (*)
False
15.
When using SET operators, the number of columns and the
data types of the columns must be identical in all of the SELECT statements
used in the query. True or False. Mark for
Review
(1)
Points
True (*)
False
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