1.
What result is returned by the following statement?
SELECT COUNT(*) FROM DUAL;
(Choose the best answer.)
a.
NULL
b.
0
c.
1
d.
None
of the above
2.
Choose
one correct statement regarding group functions.
a.
Group
functions may only be used when a GROUP BY clause is present.
b.
Group
functions can operate on multiple rows at a time.
c.
Group
functions only operate on a single row at a time.
d.
Group
functions can execute multiple times within a single group.
3.
What
value is returned after executing the following statement?
SELECT SUM(SALARY) FROM
EMPLOYEES;
Assume there are 10 employee records and each
contains a SALARY value of 100, except for 1,
which has a null value in the SALARY
field. (Choose the best answer.)
a.
900
b.
1000
c.
NULL
d.
None
of the above
4.
Which
values are returned after executing the following statement?
SELECT COUNT(*), COUNT(SALARY)
FROM EMPLOYEES;
Assume there are 10 employee records and
each contains a SALARY value of 100, except for 1,
which has a null value in their SALARY
field. (Choose all that apply.)
a.
10
and 10
b.
10
and NULL
c.
10
and 9
d. None of
the above
5.
What
value is returned after executing the following statement?
SELECT AVG(NVL(SALARY,100))
FROM EMPLOYEES;
Assume there are ten employee records and
each contains a SALARY value of 100, except for
one employee, who has a null value in the
SALARY field. (Choose the best answer.)
a.
NULL
b.
90
c.
100
d. None of
the above
6.
What
value is returned after executing the following statement?
SELECT SUM((AVG(LENGTH(NVL(SALARY,0)))))
FROM EMPLOYEES
GROUP BY SALARY;
Assume there are ten employee records and
each contains a SALARY value of 100, except for
one, which has a null value in the SALARY
field. (Choose the best answer.)
a.
An
error is returned
b.
3
c.
4
d.
None
of the above
7.
How
many records are returned by the following query?
SELECT SUM(SALARY),
DEPARTMENT_ID FROM EMPLOYEES
GROUP BY DEPARTMENT_ID;
Assume there are 11 nonnull and 1 null
unique DEPARTMENT_ID values. All records have a
nonnull SALARY value. (Choose the best
answer.)
a.
12
b.
11
c.
NULL
d.
None
of the above
8.
What
values are returned after executing the following statement?
SELECT JOB_ID, MAX_SALARY FROM
JOBS GROUP BY MAX_SALARY;
Assume that the JOBS table has ten records
with the same JOB_ID value of DBA and the same
MAX_SALARY value of 100. (Choose the best
answer.)
a.
One
row of output with the values DBA, 100
b.
Ten
rows of output with the values DBA, 100
c.
An
error is returned
d.
None
of the above
9.
How
many rows of data are returned after executing the following statement?
SELECT DEPT_ID,
SUM(NVL(SALARY,100)) FROM EMP
GROUP BY DEPT_ID HAVING
SUM(SALARY) > 400;
Assume the EMP table has ten rows and each
contains a SALARY value of 100, except for one,
which has a null value in the SALARY field.
The first and second five rows have DEPT_ID
values of 10 and 20, respectively. (Choose
the best answer.)
a.
Two
rows
b.
One
row
c.
Zero
rows
d.
None
of the above
10.
How
many rows of data are returned after executing the following statement?
SELECT DEPT_ID, SUM(SALARY)
FROM EMP GROUP BY DEPT_ID HAVING
SUM(NVL(SALARY,100)) > 400;
Assume the EMP table has ten rows and each
contains a SALARY value of 100, except for one,
which has a null value in the SALARY field.
The first and second five rows have DEPT_ID
values of 10 and 20, respectively. (Choose
the best answer.)
a.
Two
rows
b.
One
row
c.
Zero
rows
d.
None
of the above
