Oracle Database Quiz Section 10 Quiz Answer
 |
| Image Source : dqindia.com |
1. A multiple-row operator
expects how many values?
One or more (*)
Only one
Two or more
None
One or more (*)
Only one
Two or more
None
2. The salary column of the
f_staffs table contains the following values:
4000
5050
6000
11000
23000
Which of the following statements will return the last_name and first_name of those employees who earn more than 5000?
SELECT last_name, first_name FROM f_staffs WHERE salary IN
(SELECT last_name, first_name FROM f_staffs WHERE salary <5000 o:p="">
SELECT last_name, first_name FROM f_staffs WHERE salary = (SELECT salary FROM f_staffs WHERE salary < 5000);
SELECT last_name, first_name FROM f_staffs WHERE salary IN (SELECT salary FROM f_staffs WHERE salary > 5000); (*)
SELECT last_name, first_name FROM f_staffs WHERE salary = (SELECT salary FROM f_staffs WHERE salary > 5000);
4000
5050
6000
11000
23000
Which of the following statements will return the last_name and first_name of those employees who earn more than 5000?
SELECT last_name, first_name FROM f_staffs WHERE salary IN
(SELECT last_name, first_name FROM f_staffs WHERE salary <5000 o:p="">
SELECT last_name, first_name FROM f_staffs WHERE salary = (SELECT salary FROM f_staffs WHERE salary < 5000);
SELECT last_name, first_name FROM f_staffs WHERE salary IN (SELECT salary FROM f_staffs WHERE salary > 5000); (*)
SELECT last_name, first_name FROM f_staffs WHERE salary = (SELECT salary FROM f_staffs WHERE salary > 5000);
3. Examine the data in the
PAYMENT table:
This statement fails when executed:
SELECT customer_id, payment_type
FROM payment
WHERE payment_id =
(SELECT payment_id
FROM payment
WHERE payment_amount = 596.00 OR payment_date = '20-Mar-2003');
Which change could correct the problem?
Change the outer query WHERE clause to 'WHERE payment_id IN'. (*)
Remove the parentheses surrounding the nested SELECT statement.
Change the comparison operator to a single-row operator.
Remove the quotes surrounding the date value in the OR clause.
This statement fails when executed:
SELECT customer_id, payment_type
FROM payment
WHERE payment_id =
(SELECT payment_id
FROM payment
WHERE payment_amount = 596.00 OR payment_date = '20-Mar-2003');
Which change could correct the problem?
Change the outer query WHERE clause to 'WHERE payment_id IN'. (*)
Remove the parentheses surrounding the nested SELECT statement.
Change the comparison operator to a single-row operator.
Remove the quotes surrounding the date value in the OR clause.
4. Which of the following
statements contains a comparison operator that is used to restrict rows based
on a list of values returned from an inner query?
SELECT description FROM d_types WHERE code IN (SELECT type_code FROM d_songs);
SELECT description FROM d_types WHERE code = ANY (SELECT type_code FROM d_songs);
SELECT description FROM d_types WHERE code <> ALL (SELECT type_code FROM d_songs);
All of the above. (*)
SELECT description FROM d_types WHERE code IN (SELECT type_code FROM d_songs);
SELECT description FROM d_types WHERE code = ANY (SELECT type_code FROM d_songs);
SELECT description FROM d_types WHERE code <> ALL (SELECT type_code FROM d_songs);
All of the above. (*)
5. Group functions can be used
in multiple-row subqueries in the HAVING and GROUP BY clauses. True or False?
True (*)
False
True (*)
False
6. The SQL multiple-row
subquery extends the capability of the single-row syntax through the use of
which three comparison operators?
IN, ANY, and EVERY
IN, ALL, and EVERY
IN, ANY, and EQUAL
IN, ANY, and ALL (*)
IN, ANY, and EVERY
IN, ALL, and EVERY
IN, ANY, and EQUAL
IN, ANY, and ALL (*)
7. Which statement about the
<> operator is true?
The <> operator can be used when a single-row subquery returns only one row. (*)
The <> operator is NOT a valid SQL operator.
The <> operator CANNOT be used in a single-row subquery.
The <> operator returns the same result as the ANY operator in a subquery.
The <> operator can be used when a single-row subquery returns only one row. (*)
The <> operator is NOT a valid SQL operator.
The <> operator CANNOT be used in a single-row subquery.
The <> operator returns the same result as the ANY operator in a subquery.
8. Single row subqueries may
not include this operator:
>
<>
ALL (*)
=
>
<>
ALL (*)
=
9. Examine the structure of
the EMPLOYEE, DEPARTMENT, and ORDERS tables.
EMPLOYEE:
EMPLOYEE_ID NUMBER(9)
LAST_NAME VARCHAR2(25)
FIRST_NAME VARCHAR2(25)
DEPARTMENT_ID NUMBER(9)
DEPARTMENT:
DEPARTMENT_ID NUMBER(9)
DEPARTMENT_NAME VARCHAR2(25)
CREATION_DATE DATE
ORDERS:
ORDER_ID NUMBER(9)
EMPLOYEE_ID NUMBER(9)
DATE DATE
CUSTOMER_ID NUMBER(9)
You want to display all employees who had an order after the Sales department was established. Which of the following constructs would you use?
The HAVING clause
A group function
A single-row subquery (*)
A MERGE statement
EMPLOYEE:
EMPLOYEE_ID NUMBER(9)
LAST_NAME VARCHAR2(25)
FIRST_NAME VARCHAR2(25)
DEPARTMENT_ID NUMBER(9)
DEPARTMENT:
DEPARTMENT_ID NUMBER(9)
DEPARTMENT_NAME VARCHAR2(25)
CREATION_DATE DATE
ORDERS:
ORDER_ID NUMBER(9)
EMPLOYEE_ID NUMBER(9)
DATE DATE
CUSTOMER_ID NUMBER(9)
You want to display all employees who had an order after the Sales department was established. Which of the following constructs would you use?
The HAVING clause
A group function
A single-row subquery (*)
A MERGE statement
10. If you use the equality
operator (=) with a subquery, how many values can the subquery return?
Only 1 (*)
Up to 2
Up to 5
Unlimited
Only 1 (*)
Up to 2
Up to 5
Unlimited
11. The TEACHERS and
CLASS_ASSIGNMENTS tables contain these columns:
TEACHERS
TEACHER_ID NUMBER(5) Primary Key
NAME VARCHAR2 (25)
SUBJECT_ID NUMBER(5)
CLASS_ID NUMBER(5)
CLASS_ASSIGNMENTS
CLASS_ID NUMBER (5) Primary Key
TEACHER_ID NUMBER (5)
DATE
MAX_CAPACITY NUMBER (3)
All MAX_CAPACITY values are greater than 10. Which two SQL statements correctly use subqueries?
SELECT * FROM teachers WHERE teacher_id LIKE (SELECT teacher_id FROM class_assignments WHERE max_capacity > 1000);
SELECT * FROM teachers WHERE teacher_id = (SELECT teacher_id FROM class_assignments WHERE class_id = 45963); (*)
SELECT * FROM class_assignments max_capacity = (SELECT AVG(max_capacity) FROM class_assignments GROUP BY teacher_id);
SELECT * FROM teachers WHERE teacher_id = (SELECT teacher_id, class_assignments WHERE max_capacity > 0);
SELECT * FROM class_assignments WHERE max_capacity = (SELECT AVG(max_capacity) FROM class_assignments); (*)
TEACHERS
TEACHER_ID NUMBER(5) Primary Key
NAME VARCHAR2 (25)
SUBJECT_ID NUMBER(5)
CLASS_ID NUMBER(5)
CLASS_ASSIGNMENTS
CLASS_ID NUMBER (5) Primary Key
TEACHER_ID NUMBER (5)
DATE
MAX_CAPACITY NUMBER (3)
All MAX_CAPACITY values are greater than 10. Which two SQL statements correctly use subqueries?
SELECT * FROM teachers WHERE teacher_id LIKE (SELECT teacher_id FROM class_assignments WHERE max_capacity > 1000);
SELECT * FROM teachers WHERE teacher_id = (SELECT teacher_id FROM class_assignments WHERE class_id = 45963); (*)
SELECT * FROM class_assignments max_capacity = (SELECT AVG(max_capacity) FROM class_assignments GROUP BY teacher_id);
SELECT * FROM teachers WHERE teacher_id = (SELECT teacher_id, class_assignments WHERE max_capacity > 0);
SELECT * FROM class_assignments WHERE max_capacity = (SELECT AVG(max_capacity) FROM class_assignments); (*)
12. Which operator can be used
with a multiple-row subquery?
LIKE
IN (*)
=
<>
LIKE
IN (*)
=
<>
13. Which answer is INCORRECT?
The parent statement of a correlated subquery can be:
A SELECT statement
A DELETE statement
An UPDATE statement
An INSERT statement (*)
A SELECT statement
A DELETE statement
An UPDATE statement
An INSERT statement (*)
14. Oracle allows you to write
named subqueries in one single statement, as long as you start your statement
with the keyword WITH. True or False?
True (*)
False
True (*)
False
15. The Oracle server performs
a correlated subquery when the subquery references a column from a table
referred to in the parent. True or False?
True (*)
False
True (*)
False
PACKET 2
1. In a non-correlated
subquery, the outer query always executes prior to the inner query's execution.
True or False?
True
False (*)
True
False (*)
2. Subqueries are limited to
four per SQL transaction. True or False?
True
False (*)
True
False (*)
3. Which statement about the
<> operator is true?
The <> operator can be used when a single-row subquery returns only one row. (*)
The <> operator is NOT a valid SQL operator.
The <> operator CANNOT be used in a single-row subquery.
The <> operator returns the same result as the ANY operator in a subquery.
The <> operator can be used when a single-row subquery returns only one row. (*)
The <> operator is NOT a valid SQL operator.
The <> operator CANNOT be used in a single-row subquery.
The <> operator returns the same result as the ANY operator in a subquery.
4. Which statement about
subqueries is true?
Subqueries should be enclosed in double quotation marks.
Subqueries generally execute last, after the main or outer query executes.
Subqueries cannot contain group functions.
Subqueries are often used in a WHERE clause to return values for an unknown conditional value. (*)
Subqueries should be enclosed in double quotation marks.
Subqueries generally execute last, after the main or outer query executes.
Subqueries cannot contain group functions.
Subqueries are often used in a WHERE clause to return values for an unknown conditional value. (*)
5. You need to create a report
to display the names of products with a cost value greater than the average
cost of all products. Which SELECT statement should you use?
SELECT product_name FROM products WHERE cost > AVG(cost);
SELECT product_name FROM products WHERE cost > (SELECT AVG(cost) FROM products); (*)
SELECT AVG(cost), product_name FROM products WHERE cost > AVG(cost) GROUP by product_name;
SELECT product_name FROM (SELECT AVG(cost) FROM product) WHERE cost > AVG(cost);
SELECT product_name FROM products WHERE cost > AVG(cost);
SELECT product_name FROM products WHERE cost > (SELECT AVG(cost) FROM products); (*)
SELECT AVG(cost), product_name FROM products WHERE cost > AVG(cost) GROUP by product_name;
SELECT product_name FROM (SELECT AVG(cost) FROM product) WHERE cost > AVG(cost);
6. The TEACHERS and
CLASS_ASSIGNMENTS tables contain these columns:
TEACHERS TEACHER_ID NUMBER(5) Primary Key NAME VARCHAR2 (25) SUBJECT_ID NUMBER(5) CLASS_ID NUMBER(5)
CLASS_ASSIGNMENTS CLASS_ID NUMBER (5) Primary Key TEACHER_ID NUMBER (5) DATE MAX_CAPACITY NUMBER (3)
All MAX_CAPACITY values are greater than 10. Which two SQL statements correctly use subqueries? (Choose two.)
SELECT * FROM class_assignments max_capacity = (SELECT AVG(max_capacity) FROM class_assignments GROUP BY teacher_id);
SELECT * FROM teachers WHERE teacher_id = (SELECT teacher_id FROM class_assignments WHERE class_id = 45963); (*)
SELECT * FROM teachers WHERE teacher_id LIKE (SELECT teacher_id FROM class_assignments WHERE max_capacity > 1000);
SELECT * FROM class_assignments WHERE max_capacity = (SELECT AVG(max_capacity) FROM class_assignments); (*)
SELECT * FROM teachers WHERE teacher_id = (SELECT teacher_id, class_assignments WHERE max_capacity > 0);
TEACHERS TEACHER_ID NUMBER(5) Primary Key NAME VARCHAR2 (25) SUBJECT_ID NUMBER(5) CLASS_ID NUMBER(5)
CLASS_ASSIGNMENTS CLASS_ID NUMBER (5) Primary Key TEACHER_ID NUMBER (5) DATE MAX_CAPACITY NUMBER (3)
All MAX_CAPACITY values are greater than 10. Which two SQL statements correctly use subqueries? (Choose two.)
SELECT * FROM class_assignments max_capacity = (SELECT AVG(max_capacity) FROM class_assignments GROUP BY teacher_id);
SELECT * FROM teachers WHERE teacher_id = (SELECT teacher_id FROM class_assignments WHERE class_id = 45963); (*)
SELECT * FROM teachers WHERE teacher_id LIKE (SELECT teacher_id FROM class_assignments WHERE max_capacity > 1000);
SELECT * FROM class_assignments WHERE max_capacity = (SELECT AVG(max_capacity) FROM class_assignments); (*)
SELECT * FROM teachers WHERE teacher_id = (SELECT teacher_id, class_assignments WHERE max_capacity > 0);
7. When creating a report of
all employees earning more than the average salary for their department, a
__________ ____________ can be used to first calculate the average salary of
each department, and then compare the salary for each employee to the average
salary of that employeeﾒs department.
WITH CLAUSE
GROUP BY
CORRELATED SUBQUERY (*)
WITH CLAUSE
GROUP BY
CORRELATED SUBQUERY (*)
8. Which statement is false?
The WITH clause retrieves the results of one or more query blocks.
The WITH clause stores the results for the user who runs the query.
The WITH clause decreases performance. (*)
The WITH clause makes the query simple to read.
The WITH clause retrieves the results of one or more query blocks.
The WITH clause stores the results for the user who runs the query.
The WITH clause decreases performance. (*)
The WITH clause makes the query simple to read.
9. Correlated Subqueries must
reference the same tables in both the inner and outer queries.
True
False (*)
True
False (*)
10. When a multiple-row
subquery uses the NOT IN operator (equivalent to <>ALL), if one of the
values returned by the inner query is a null value, the entire query returns:
All rows that were selected by the inner query including the null values
No rows returned (*)
All rows that were selected by the inner query minus the null values
A list of Nulls
All rows that were selected by the inner query including the null values
No rows returned (*)
All rows that were selected by the inner query minus the null values
A list of Nulls
11. Examine the structures of
the PARTS and MANUFACTURERS tables:
PARTS: PARTS_ID VARCHAR2(25) PK PARTS_NAME VARCHAR2(50) MANUFACTURERS_ID NUMBER COST NUMBER(5,2) PRICE NUMBER(5,2)
MANUFACTURERS: ID NUMBER PK NAME VARCHAR2(30) LOCATION VARCHAR2(20)
Assume that the tables have been populated with data including 100 rows in the PARTS table, and 20 rows in the MANUFACTURERS table. Which SQL statement correctly uses a subquery?
SELECT parts_name, price, cost FROM parts WHERE manufacturers_id != (SELECT id FROM manufacturers WHERE LOWER(name) = 'cost plus');
SELECT parts_name, price, cost FROM parts WHERE manufacturers_id IN (SELECT id FROM manufacturers m JOIN parts p ON (m.id = p.manufacturers_id)); (*)
UPDATE parts SET price = price * 1.15 WHERE manufacturers_id = (SELECT id FROM manufacturers WHERE UPPER(location) IN("ATLANTA", "BOSTON", "DALLAS"));
SELECT parts_name FROM (SELECT AVG(cost) FROM manufacturers) WHERE cost > AVG(cost);
PARTS: PARTS_ID VARCHAR2(25) PK PARTS_NAME VARCHAR2(50) MANUFACTURERS_ID NUMBER COST NUMBER(5,2) PRICE NUMBER(5,2)
MANUFACTURERS: ID NUMBER PK NAME VARCHAR2(30) LOCATION VARCHAR2(20)
Assume that the tables have been populated with data including 100 rows in the PARTS table, and 20 rows in the MANUFACTURERS table. Which SQL statement correctly uses a subquery?
SELECT parts_name, price, cost FROM parts WHERE manufacturers_id != (SELECT id FROM manufacturers WHERE LOWER(name) = 'cost plus');
SELECT parts_name, price, cost FROM parts WHERE manufacturers_id IN (SELECT id FROM manufacturers m JOIN parts p ON (m.id = p.manufacturers_id)); (*)
UPDATE parts SET price = price * 1.15 WHERE manufacturers_id = (SELECT id FROM manufacturers WHERE UPPER(location) IN("ATLANTA", "BOSTON", "DALLAS"));
SELECT parts_name FROM (SELECT AVG(cost) FROM manufacturers) WHERE cost > AVG(cost);
12. You need to create a SELECT
statement that contains a multiple-row subquery. Which comparison operator(s)
can you use?
=, <, and >
IN, ANY, and ALL (*)
LIKE
BETWEENﾅANDﾅ
=, <, and >
IN, ANY, and ALL (*)
LIKE
BETWEENﾅANDﾅ
13. You are looking for
Executive information using a subquery.
What will the following SQL statement display?
SELECT department_id, last_name, job_id
FROM employees
WHERE department_id IN
(SELECT department_id FROM departments WHERE department_name ='Executive');
The department ID, department name, and last name for every employee in the Executive department
The department ID, last name, and department name for every Executive in the employees table
The department ID, last name, and job ID from departments for Executive employees
The department ID, last name, and job ID for every employee in the Executive department (*)
What will the following SQL statement display?
SELECT department_id, last_name, job_id
FROM employees
WHERE department_id IN
(SELECT department_id FROM departments WHERE department_name ='Executive');
The department ID, department name, and last name for every employee in the Executive department
The department ID, last name, and department name for every Executive in the employees table
The department ID, last name, and job ID from departments for Executive employees
The department ID, last name, and job ID for every employee in the Executive department (*)
14. Evaluate the structure of
the EMPLOYEES and DEPART_HIST tables:
EMPLOYEES
EMPLOYEE_ID NUMBER(9)
LAST_NAME VARCHAR2(25)
FIRST_NAME VARCHAR2(25)
DEPARTMENT_ID NUMBER(9)
MANAGER_ID NUMBER(9)
SALARY NUMBER(7,2)
DEPART_HIST:
EMPLOYEE_ID NUMBER(9)
OLD_DEPT_ID NUMBER(9)
NEW_DEPT_ID NUMBER(9)
CHANGE_DATE DATE
You want to generate a list of employees who are in department 10, but used to be in department 15. Which query should you use?
SELECT employee_id, last_name, first_name, department_id
FROM employees
WHERE (employee_id, department_id) =
(SELECT employee_id, new_dept_id
FROM depart_hist
WHERE new_dept_id = 15);
SELECT employee_id, last_name, first_name, department_id
FROM employees
WHERE (employee_id, department_id) IN
(SELECT employee_id, dept_id
FROM employees
WHERE old_dept_id = 15);
SELECT employee_id, last_name, first_name, department_id
FROM employees
WHERE (employee_id) IN
(SELECT employee_id
FROM employee_hist
WHERE old_dept_id = 15);
SELECT employee_id, last_name, first_name, department_id
FROM employees
WHERE (employee_id, department_id) IN
(SELECT employee_id, new_dept_id
FROM depart_hist
WHERE old_dept_id = 15) AND new_dept_id = 10; (*)
EMPLOYEES
EMPLOYEE_ID NUMBER(9)
LAST_NAME VARCHAR2(25)
FIRST_NAME VARCHAR2(25)
DEPARTMENT_ID NUMBER(9)
MANAGER_ID NUMBER(9)
SALARY NUMBER(7,2)
DEPART_HIST:
EMPLOYEE_ID NUMBER(9)
OLD_DEPT_ID NUMBER(9)
NEW_DEPT_ID NUMBER(9)
CHANGE_DATE DATE
You want to generate a list of employees who are in department 10, but used to be in department 15. Which query should you use?
SELECT employee_id, last_name, first_name, department_id
FROM employees
WHERE (employee_id, department_id) =
(SELECT employee_id, new_dept_id
FROM depart_hist
WHERE new_dept_id = 15);
SELECT employee_id, last_name, first_name, department_id
FROM employees
WHERE (employee_id, department_id) IN
(SELECT employee_id, dept_id
FROM employees
WHERE old_dept_id = 15);
SELECT employee_id, last_name, first_name, department_id
FROM employees
WHERE (employee_id) IN
(SELECT employee_id
FROM employee_hist
WHERE old_dept_id = 15);
SELECT employee_id, last_name, first_name, department_id
FROM employees
WHERE (employee_id, department_id) IN
(SELECT employee_id, new_dept_id
FROM depart_hist
WHERE old_dept_id = 15) AND new_dept_id = 10; (*)
15. Which of the following best
describes the meaning of the ANY operator?
Equal to any member in the list
Equal to each value in the list
Compare value to the first value returned by the subquery
Compare value to each value returned by the subquery (*)
Equal to any member in the list
Equal to each value in the list
Compare value to the first value returned by the subquery
Compare value to each value returned by the subquery (*)
1. Table aliases must be used
when you are writing correlated subqueries. (True or false?)
True
False (*)
True
False (*)
2. Oracle allows you to write
named subqueries in one single statement, as long as you start your statement
with the keyword WITH. True or False?
True (*)
False
True (*)
False
3. Which statement is false?
The WITH clause decreases performance. (*)
The WITH clause makes the query simple to read.
The WITH clause stores the results for the user who runs the query.
The WITH clause retrieves the results of one or more query blocks.
The WITH clause decreases performance. (*)
The WITH clause makes the query simple to read.
The WITH clause stores the results for the user who runs the query.
The WITH clause retrieves the results of one or more query blocks.
4. Subqueries can only be
placed in the WHERE clause. True or False?
True
False (*)
True
False (*)
5. Which operator can be used
with a multiple-row subquery?
IN (*)
LIKE
<>
=
IN (*)
LIKE
<>
=
6. Using a subquery in which
clause will return a syntax error?
WHERE
FROM
HAVING
You can use subqueries in all of the above clauses. (*)
WHERE
FROM
HAVING
You can use subqueries in all of the above clauses. (*)
7. Which comparison operator
can only be used with a single-row subquery?
IN
<> (*)
ANY
ALL
IN
<> (*)
ANY
ALL
8. Subqueries are limited to
four per SQL transaction. True or False?
True
False (*)
True
False (*)
9. You need to produce a
report that contains all employee-related information for those employees who
have Brad Carter as a supervisor. However, you are not sure which supervisor ID
belongs to Brad Carter. Which query should you issue to accomplish this task?
SELECT * FROM employees WHERE supervisor_id = (SELECT supervisor_id FROM employees WHERE last_name = 'Carter');
SELECT * FROM supervisors WHERE supervisor_id = (SELECT supervisor_id FROM employees WHERE last_name = 'Carter');
SELECT * FROM employees WHERE supervisor_id = (SELECT employee_id FROM employees WHERE last_name = 'Carter'); (*)
SELECT * FROM supervisors WHERE supervisor_id = (SELECT employee_id FROM supervisors WHERE last_name = 'Carter');
SELECT * FROM employees WHERE supervisor_id = (SELECT supervisor_id FROM employees WHERE last_name = 'Carter');
SELECT * FROM supervisors WHERE supervisor_id = (SELECT supervisor_id FROM employees WHERE last_name = 'Carter');
SELECT * FROM employees WHERE supervisor_id = (SELECT employee_id FROM employees WHERE last_name = 'Carter'); (*)
SELECT * FROM supervisors WHERE supervisor_id = (SELECT employee_id FROM supervisors WHERE last_name = 'Carter');
10. Which operator or keyword
cannot be used with a multiple-row subquery?
>
= (*)
ANY
ALL
>
= (*)
ANY
ALL
11. When a multiple-row
subquery uses the NOT IN operator (equivalent to <>ALL), if one of the
values returned by the inner query is a null value, the entire query returns:
A list of Nulls
No rows returned (*)
All rows that were selected by the inner query including the null values
All rows that were selected by the inner query minus the null values
A list of Nulls
No rows returned (*)
All rows that were selected by the inner query including the null values
All rows that were selected by the inner query minus the null values
12. Evaluate this SQL
statement:
SELECT employee_id, last_name, salary FROM employees WHERE department_id IN (SELECT department_id FROM employees WHERE salary > 30000 AND salary < 50000);
Which values will be displayed?
Only employees who earn more than $30,000. All employees who work in a department with employees who earn more than $30,000 and more than $50,000.
All employees who work in a department with employees who earn more than $30,000, but less than $50,000. (*)
Only employees who earn less than $50,000.
SELECT employee_id, last_name, salary FROM employees WHERE department_id IN (SELECT department_id FROM employees WHERE salary > 30000 AND salary < 50000);
Which values will be displayed?
Only employees who earn more than $30,000. All employees who work in a department with employees who earn more than $30,000 and more than $50,000.
All employees who work in a department with employees who earn more than $30,000, but less than $50,000. (*)
Only employees who earn less than $50,000.
13. Group functions can be used
in multiple-row subqueries in the HAVING and GROUP BY clauses.
True (*)
False
True (*)
False
14. The SQL multiple-row
subquery extends the capability of the single-row syntax through the use of
which three comparison operators?
IN, ANY, and ALL (*)
IN, ANY, and EVERY
IN, ALL, and EVERY
IN, ANY, and EQUAL
IN, ANY, and ALL (*)
IN, ANY, and EVERY
IN, ALL, and EVERY
IN, ANY, and EQUAL
15. Evaluate the structure of
the EMPLOYEES and DEPART_HIST tables:
EMPLOYEES
EMPLOYEE_ID NUMBER(9)
LAST_NAME VARCHAR2(25)
FIRST_NAME VARCHAR2(25)
DEPARTMENT_ID NUMBER(9)
MANAGER_ID NUMBER(9)
SALARY NUMBER(7,2)
DEPART_HIST:
EMPLOYEE_ID NUMBER(9)
OLD_DEPT_ID NUMBER(9)
NEW_DEPT_ID NUMBER(9)
CHANGE_DATE DATE
You want to generate a list of employees who are in department 10, but used to be in department 15. Which query should you use?
SELECT employee_id, last_name, first_name, department_id FROM employees WHERE (employee_id, department_id) = (SELECT employee_id, new_dept_id FROM depart_hist WHERE new_dept_id = 15);
SELECT employee_id, last_name, first_name, department_id FROM employees WHERE (employee_id, department_id) IN (SELECT employee_id, dept_id FROM employees WHERE old_dept_id = 15);
SELECT employee_id, last_name, first_name, department_id FROM employees WHERE (employee_id, department_id) IN (SELECT employee_id, new_dept_id FROM depart_hist WHERE old_dept_id = 15) AND new_dept_id = 10; (*)
SELECT employee_id, last_name, first_name, department_id FROM employees WHERE (employee_id) IN (SELECT employee_id FROM employee_hist WHERE old_dept_id = 15);
EMPLOYEES
EMPLOYEE_ID NUMBER(9)
LAST_NAME VARCHAR2(25)
FIRST_NAME VARCHAR2(25)
DEPARTMENT_ID NUMBER(9)
MANAGER_ID NUMBER(9)
SALARY NUMBER(7,2)
DEPART_HIST:
EMPLOYEE_ID NUMBER(9)
OLD_DEPT_ID NUMBER(9)
NEW_DEPT_ID NUMBER(9)
CHANGE_DATE DATE
You want to generate a list of employees who are in department 10, but used to be in department 15. Which query should you use?
SELECT employee_id, last_name, first_name, department_id FROM employees WHERE (employee_id, department_id) = (SELECT employee_id, new_dept_id FROM depart_hist WHERE new_dept_id = 15);
SELECT employee_id, last_name, first_name, department_id FROM employees WHERE (employee_id, department_id) IN (SELECT employee_id, dept_id FROM employees WHERE old_dept_id = 15);
SELECT employee_id, last_name, first_name, department_id FROM employees WHERE (employee_id, department_id) IN (SELECT employee_id, new_dept_id FROM depart_hist WHERE old_dept_id = 15) AND new_dept_id = 10; (*)
SELECT employee_id, last_name, first_name, department_id FROM employees WHERE (employee_id) IN (SELECT employee_id FROM employee_hist WHERE old_dept_id = 15);
1. The Oracle server performs
a correlated subquery when the subquery references a column from a table
referred to in the parent. True or False?
True (*)
False
True (*)
False
2. The WITH clause is a way of
creating extra tables in the database. (True or False?)
True
False (*)
True
False (*)
3. In a correlated subquery,
the outer and inner queries are joined on one or more columns. (True or False?)
True (*)
False
True (*)
False
4. If a single-row subquery
returns a null value and uses the equality comparison operator, what will the
outer query return?
All the rows in the table
No rows (*)
A null value
An error
All the rows in the table
No rows (*)
A null value
An error
5. Examine the structure of the
EMPLOYEE, DEPARTMENT, and ORDERS tables.
EMPLOYEE:
EMPLOYEE_ID NUMBER(9)
LAST_NAME VARCHAR2(25)
FIRST_NAME VARCHAR2(25)
DEPARTMENT_ID NUMBER(9)
DEPARTMENT:
DEPARTMENT_ID NUMBER(9)
DEPARTMENT_NAME VARCHAR2(25)
CREATION_DATE DATE
ORDERS:
ORDER_ID NUMBER(9)
EMPLOYEE_ID NUMBER(9)
DATE DATE
CUSTOMER_ID NUMBER(9)
You want to display all employees who had an order after the Sales department was established. Which of the following constructs would you use?
A MERGE statement
A group function
The HAVING clause
A single-row subquery (*)
EMPLOYEE:
EMPLOYEE_ID NUMBER(9)
LAST_NAME VARCHAR2(25)
FIRST_NAME VARCHAR2(25)
DEPARTMENT_ID NUMBER(9)
DEPARTMENT:
DEPARTMENT_ID NUMBER(9)
DEPARTMENT_NAME VARCHAR2(25)
CREATION_DATE DATE
ORDERS:
ORDER_ID NUMBER(9)
EMPLOYEE_ID NUMBER(9)
DATE DATE
CUSTOMER_ID NUMBER(9)
You want to display all employees who had an order after the Sales department was established. Which of the following constructs would you use?
A MERGE statement
A group function
The HAVING clause
A single-row subquery (*)
6. Single row subqueries may
not include this operator:
=
>
<>
ALL (*)
=
>
<>
ALL (*)
7. The SQL multiple-row
subquery extends the capability of the single-row syntax through the use of
which three comparison operators?
IN, ANY, and EQUAL
IN, ANY, and ALL (*)
IN, ALL, and EVERY
IN, ANY, and EVERY
IN, ANY, and EQUAL
IN, ANY, and ALL (*)
IN, ALL, and EVERY
IN, ANY, and EVERY
8. Which of the following best
describes the meaning of the ANY operator?
Equal to each value in the list
Equal to any member in the list
Compare value to the first value returned by the subquery
Compare value to each value returned by the subquery (*)
Equal to each value in the list
Equal to any member in the list
Compare value to the first value returned by the subquery
Compare value to each value returned by the subquery (*)
9. Which comparison operator
would you use to compare a value to every value returned by a subquery?
IN
ANY
SOME
ALL (*)
IN
ANY
SOME
ALL (*)
10. A multiple-row operator
expects how many values?
One or more (*)
Only one
Two or more
None
One or more (*)
Only one
Two or more
None
11. Evaluate this SELECT
statement: SELECT player_id, name FROM players WHERE team_id IN (SELECT team_id
FROM teams WHERE team_id > 300 AND salary_cap > 400000);
What would happen if the inner query returned a NULL value?
A syntax error in the outer query would be returned.
No rows would be returned by the outer query. (*)
A syntax error in the inner query would be returned.
All the rows in the PLAYER table would be returned by the outer query.
What would happen if the inner query returned a NULL value?
A syntax error in the outer query would be returned.
No rows would be returned by the outer query. (*)
A syntax error in the inner query would be returned.
All the rows in the PLAYER table would be returned by the outer query.
12. You need to create a SELECT
statement that contains a multiple-row subquery. Which comparison operator(s)
can you use?
LIKE
BETWEENﾅANDﾅ
IN, ANY, and ALL (*)
=, <, and >
LIKE
BETWEENﾅANDﾅ
IN, ANY, and ALL (*)
=, <, and >
13. You need to display all the
players whose salaries are greater than or equal to John Brown's salary. Which
comparison operator should you use?
=
<=
>= (*)
>
=
<=
>= (*)
>
14. What will the following
statement return:
SELECT last_name, salary FROM employees WHERE salary < (SELECT salary FROM employees WHERE employee_id = 103);
A list of last_names and salaries of employees who make more than employee 103
A list of last_names and salaries of employees who make less than employee 103 (*)
A list of first_names and salaries of employees making less than employee 103
Nothing. It is an invalid statement.
SELECT last_name, salary FROM employees WHERE salary < (SELECT salary FROM employees WHERE employee_id = 103);
A list of last_names and salaries of employees who make more than employee 103
A list of last_names and salaries of employees who make less than employee 103 (*)
A list of first_names and salaries of employees making less than employee 103
Nothing. It is an invalid statement.
15. Which of the following is
TRUE regarding the order of subquery execution?
The subquery executes once after the main query.
The result of the main query is used with the subquery.
The subquery executes once before the main query. (*)
The outer query is executed first.
The subquery executes once after the main query.
The result of the main query is used with the subquery.
The subquery executes once before the main query. (*)
The outer query is executed first.
1. Examine the structure of
the EMPLOYEE, DEPARTMENT, and ORDERS tables.
EMPLOYEE:
EMPLOYEE_ID NUMBER(9)
LAST_NAME VARCHAR2(25)
FIRST_NAME VARCHAR2(25)
DEPARTMENT_ID NUMBER(9)
DEPARTMENT:
DEPARTMENT_ID NUMBER(9)
DEPARTMENT_NAME VARCHAR2(25)
CREATION_DATE DATE
ORDERS:
ORDER_ID NUMBER(9)
EMPLOYEE_ID NUMBER(9)
DATE DATE
CUSTOMER_ID NUMBER(9)
You want to display all employees who had an order after the Sales department was established. Which of the following constructs would you use?
A group function
The HAVING clause
A single-row subquery (*)
A MERGE statement
EMPLOYEE:
EMPLOYEE_ID NUMBER(9)
LAST_NAME VARCHAR2(25)
FIRST_NAME VARCHAR2(25)
DEPARTMENT_ID NUMBER(9)
DEPARTMENT:
DEPARTMENT_ID NUMBER(9)
DEPARTMENT_NAME VARCHAR2(25)
CREATION_DATE DATE
ORDERS:
ORDER_ID NUMBER(9)
EMPLOYEE_ID NUMBER(9)
DATE DATE
CUSTOMER_ID NUMBER(9)
You want to display all employees who had an order after the Sales department was established. Which of the following constructs would you use?
A group function
The HAVING clause
A single-row subquery (*)
A MERGE statement
2. If a single-row subquery
returns a null value and uses the equality comparison operator, what will the
outer query return?
No rows (*)
A null value
All the rows in the table
An error
No rows (*)
A null value
All the rows in the table
An error
3. The result of this
statement will be:
SELECT last_name, job_id, salary, department_id
FROM employees
WHERE job_id =
(SELECT job_id
FROM employees
WHERE employee_id = 141) AND
department_id =
(SELECT department_id
FROM departments
WHERE location_id =1500);
Only the employees whose job id matches employee 141 and who work in location 1500 (*)
All employees from Location 1500 will be displayed
All employees with the department id of 141
An error since you canﾒt get data from two tables in the same subquery
SELECT last_name, job_id, salary, department_id
FROM employees
WHERE job_id =
(SELECT job_id
FROM employees
WHERE employee_id = 141) AND
department_id =
(SELECT department_id
FROM departments
WHERE location_id =1500);
Only the employees whose job id matches employee 141 and who work in location 1500 (*)
All employees from Location 1500 will be displayed
All employees with the department id of 141
An error since you canﾒt get data from two tables in the same subquery
4. Which answer is INCORRECT?
The parent statement of a correlated subquery can be:
A SELECT statement
An UPDATE statement
A DELETE statement
An INSERT statement (*)
A SELECT statement
An UPDATE statement
A DELETE statement
An INSERT statement (*)
5. Table aliases must be used
when you are writing correlated subqueries. (True or false?)
True
False (*)
True
False (*)
6. The WITH clause enables a
SELECT statement to define the subquery block at the start of the query,
process the block just once, label the results, and then refer to the results
multiple times. True or False?
True (*)
False
True (*)
False
7. Which of the following
statements is a true guideline for using subqueries?
The outer and inner queries can reference more than one table. They can get data from different tables. (*)
Do not enclose the subquery in parentheses.
Only one WHERE clause can be used for a SELECT statement, and if specified, it must be the outer query.
Place the subquery on the left side of the comparison condition.
The outer and inner queries can reference more than one table. They can get data from different tables. (*)
Do not enclose the subquery in parentheses.
Only one WHERE clause can be used for a SELECT statement, and if specified, it must be the outer query.
Place the subquery on the left side of the comparison condition.
8. You need to create a report
to display the names of products with a cost value greater than the average
cost of all products. Which SELECT statement should you use?
SELECT product_name
FROM (SELECT AVG(cost) FROM product)
WHERE cost > AVG(cost);
SELECT AVG(cost), product_name
FROM products
WHERE cost > AVG(cost)
GROUP by product_name;
SELECT product_name
FROM products
WHERE cost > (SELECT AVG(cost)
FROM products); (*)
SELECT product_name
FROM products
WHERE cost > AVG(cost);
SELECT product_name
FROM (SELECT AVG(cost) FROM product)
WHERE cost > AVG(cost);
SELECT AVG(cost), product_name
FROM products
WHERE cost > AVG(cost)
GROUP by product_name;
SELECT product_name
FROM products
WHERE cost > (SELECT AVG(cost)
FROM products); (*)
SELECT product_name
FROM products
WHERE cost > AVG(cost);
9. You need to display all the
players whose salaries are greater than or equal to John Brown's salary. Which
comparison operator should you use?
>= (*)
=
<=
>
>= (*)
=
<=
>
10. Evaluate this SELECT
statement:
SELECT customer_id, name
FROM customer
WHERE customer_id IN
(SELECT customer_id
FROM customer
WHERE state_id = 'GA' AND credit_limit > 500.00);
What would happen if the inner query returned null?
Only the rows with CUSTOMER_ID values equal to null would be selected.
No rows would be returned by the outer query. (*)
An error would be returned.
All the rows in the table would be selected.
SELECT customer_id, name
FROM customer
WHERE customer_id IN
(SELECT customer_id
FROM customer
WHERE state_id = 'GA' AND credit_limit > 500.00);
What would happen if the inner query returned null?
Only the rows with CUSTOMER_ID values equal to null would be selected.
No rows would be returned by the outer query. (*)
An error would be returned.
All the rows in the table would be selected.
11. Which statement about the
ANY operator, when used with a multiple-row subquery, is true?
The ANY operator is a synonym for the ALL operator.
The ANY operator can be used with the LIKE and IN operators.
The ANY operator compares every value returned by the subquery. (*)
The ANY operator can be used with the DISTINCT keyword.
The ANY operator is a synonym for the ALL operator.
The ANY operator can be used with the LIKE and IN operators.
The ANY operator compares every value returned by the subquery. (*)
The ANY operator can be used with the DISTINCT keyword.
12. Multiple-row subqueries
must have NOT, IN, or ANY in the WHERE clause of the inner query. True or
False?
True
False (*)
True
False (*)
13. Group functions can be used
in multiple-row subqueries in the HAVING and GROUP BY clauses. True or False?
True (*)
False
True (*)
False
14. The salary column of the
f_staffs table contains the following values:
4000
5050
6000
11000
23000
Which of the following statements will return the last_name and first_name of those employees who earn more than 5000?
SELECT last_name, first_name
FROM f_staffs
WHERE salary = (SELECT salary FROM f_staffs WHERE salary < 5000);
SELECT last_name, first_name
FROM f_staffs
WHERE salary = (SELECT salary FROM f_staffs WHERE salary > 5000);
SELECT last_name, first_name
FROM f_staffs
WHERE salary IN (SELECT salary FROM f_staffs WHERE salary > 5000);
(*)
SELECT last_name, first_name
FROM f_staffs
WHERE salary IN
(SELECT last_name, first_name FROM f_staffs WHERE salary <5000 o:p="">
4000
5050
6000
11000
23000
Which of the following statements will return the last_name and first_name of those employees who earn more than 5000?
SELECT last_name, first_name
FROM f_staffs
WHERE salary = (SELECT salary FROM f_staffs WHERE salary < 5000);
SELECT last_name, first_name
FROM f_staffs
WHERE salary = (SELECT salary FROM f_staffs WHERE salary > 5000);
SELECT last_name, first_name
FROM f_staffs
WHERE salary IN (SELECT salary FROM f_staffs WHERE salary > 5000);
(*)
SELECT last_name, first_name
FROM f_staffs
WHERE salary IN
(SELECT last_name, first_name FROM f_staffs WHERE salary <5000 o:p="">
15. You need to create a SELECT
statement that contains a multiple-row subquery. Which comparison operator(s)
can you use?
LIKE
IN, ANY, and ALL (*)
=, <, and >
BETWEENﾅANDﾅ
LIKE
IN, ANY, and ALL (*)
=, <, and >
BETWEENﾅANDﾅ