Section 10 Quiz Oracle Database Programming with SQL

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? >= = <= >

>=

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.

A list of last_names and salaries of employees who make less than employee 103

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

A single-row subquery

Single row subqueries may not include this operator: > <> ALL =

ALL

Which comparison operator would you use to compare a value to every value returned by a subquery? IN ANY SOME ALL

ALL

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.

All employees who work in a department with employees who earn more than $30,000, but less than $50,000.

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.

All of the above.

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

An INSERT statement

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

An INSERT statement

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's department. WITH CLAUSE GROUP BY CORRELATED SUBQUERY

CORRELATED SUBQUERY

Examine the data in the PAYMENT table: PAYMENT_ID CUSTOMER_ID PAYMENT_DATE PAYMENT_TYPE PAYMENT_AMOUNT 86590586 8908090 10-Jun-2003 BASIC 859.00 89453485 8549038 15-Feb-2003 INTEREST 596.00 85490345 5489304 20-Mar-2003 BASIC 568.00 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.

Change the outer query WHERE clause to 'WHERE payment_id IN'.

Correlated Subqueries must reference the same tables in both the inner and outer queries. True or False?

False

In a non-correlated subquery, the outer query always executes prior to the inner query's execution. True or False?

False

Multiple-row subqueries must have NOT, IN, or ANY in the WHERE clause of the inner query. True or False?

False

Subqueries are limited to four per SQL transaction. True or False?

False

Subqueries can only be placed in the WHERE clause. True or False?

False

Table aliases must be used when you are writing correlated subqueries. True or false?

False

The WITH clause is a way of creating extra tables in the database. (True or False?)

False

Which operator can be used with a multiple-row subquery? LIKE IN = <>

IN

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 ALL

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 AND

IN, ANY, and ALL

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

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

No rows returned

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.

No rows would be returned by the outer query.

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.

No rows would be returned by the outer query.

A multiple-row operator expects how many values? One or more Only one Two or more None

One or more

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

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

Only the employees whose job id matches employee 141 and who work in location 1500

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 employee_id FROM employees WHERE last_name = 'Carter');

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 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);

SELECT * FROM teachers WHERE teacher_id = (SELECT teacher_id FROM class_assignments WHERE class_id = 45963); SELECT * FROM class_assignments WHERE max_capacity = (SELECT AVG(max_capacity) FROM class_assignments);

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;

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;

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="">

SELECT last_name, first_name FROM f_staffs WHERE salary IN (SELECT salary FROM f_staffs WHERE salary > 5000);

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);

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));

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 > (SELECT AVG(cost) FROM products);

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 are often used in a WHERE clause to return values for an unknown conditional value.

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.

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 compares every value returned by the subquery.

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 decreases performance.

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

The department ID, last name, and job ID for every employee in the Executive department

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.

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 before the main query. (*)

Group functions can be used in multiple-row subqueries in the HAVING and GROUP BY clauses. True or False?

True

In a correlated subquery, the outer and inner queries are joined on one or more columns. (True or False?)

True

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

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

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

Using a subquery in which clause will return a syntax error? WHERE FROM HAVING You can use subqueries in all of the above clauses.

You can use subqueries in all of the above clauses.