Test Your Oracle INNER JOIN Skills with This SQL Quiz

Progress

True / False

n Oracle, an INNER JOIN returns only the rows that have matching values in both tables.

True False

The INNER JOIN returns only the rows where there is a match in both tables based on the specified join condition.

True / False

The INNER JOIN keyword is optional in Oracle; you can achieve the same result with the JOIN keyword alone.

True False

In Oracle, INNER JOIN is synonymous with JOIN. Using JOIN alone performs an inner join by default.

True / False

In Oracle, the INNER JOIN can only be used with two tables.

True False

The INNER JOIN can be used with more than two tables by chaining multiple join operations.

True / False

In Oracle, you can use column aliases in the ON clause of an INNER JOIN to make the query more readable.

True False

Column aliases can be used in the ON clause to improve readability and maintainability of the query.

True / False

In Oracle, the INNER JOIN can be combined with the WHERE clause to further filter the joined results.

True False

The INNER JOIN can be combined with the WHERE clause to apply additional filtering criteria to the joined results.

True / False

In Oracle, INNER JOIN is generally more efficient than LEFT JOIN when you only need matching rows from both tables.

True False

INNER JOIN is more efficient than LEFT JOIN when only matching rows are needed, as it does not include non-matching rows from the left table.

True / False

In Oracle, using INNER JOIN on large tables without proper indexing can lead to poor query performance.

True False

Without proper indexing, INNER JOIN on large tables can result in slow query performance due to the need to compare many rows.

True / False

In Oracle, you can perform an INNER JOIN on columns with different data types as long as they are implicitly convertible.

True False

Oracle allows INNER JOIN on columns with different data types if they can be implicitly converted to a common type.

True / False

In Oracle, an INNER JOIN can be used within a subquery to refine the results of the main query.

True False

An INNER JOIN can be used within a subquery to create a derived set of data that is then used by the main query.

Q10

True / False

The Oracle Certified Professional (OCP) exam includes knowledge on using INNER JOIN effectively, understanding its syntax, and optimizing its performance in complex SQL queries.

True False

The OCP certification covers advanced topics, including the effective use of INNER JOIN, understanding its syntax, and optimizing its performance in complex SQL queries.

Q11

Single Choice

: What is the primary purpose of an INNER JOIN in ORACLE SQL?

To combine rows from two or more tables based on a related column To delete rows from multiple tables To create new tablesTo update rows in a single table

An INNER JOIN in Oracle SQL is used to combine rows from two or more tables where there is a match between columns in those tables.

Q12

Single Choice

What happens if there are no matching rows in an INNER JOIN in ORACLE SQL?

The query returns NULL values for non-matching rows The query returns all rows from the first table The query returns no rowsThe query returns only rows from the second table

If there are no matching rows between the joined tables in an INNER JOIN, no rows are returned in the result set.

Q13

Single Choice

Which of the following is a basic syntax for an INNER JOIN in ORACLE SQL?

SELECT columns FROM table1 INNER JOIN table2 ON table1.column = table2.column; SELECT columns FROM table1 OUTER JOIN table2 ON table1.column = table2.column; SELECT columns FROM table1 CROSS JOIN table2;SELECT columns FROM table1 JOIN table2 WHERE table1.column = table2.column;

The correct syntax for an INNER JOIN includes the INNER JOIN keyword followed by the ON clause to specify the matching columns.

Q14

Single Choice

Given the following ORACLE SQL query:What will this query return?

A list of all employees with their department names A list of all departments with employee IDs Only the department namesAll employees without their department names

The query performs an INNER JOIN between the employees and departments tables, returning employee IDs and their corresponding department names.

Q15

Single Choice

Which of the following ORACLE SQL queries would you use to return only those rows where both tables have matching values?

SELECT * FROM table1 INNER JOIN table2 ON table1.column = table2.column; SELECT * FROM table1 LEFT JOIN table2 ON table1.column = table2.column; SELECT * FROM table1 RIGHT JOIN table2 ON table1.column = table2.column;SELECT * FROM table1 FULL JOIN table2 ON table1.column = table2.column;

An INNER JOIN only returns rows where there is a match between the columns in the joined tables.

Q16

Single Choice

Consider the following ORACLE SQL query:What is the purpose of this query?

SQL Code

SELECT p.product_name, o.order_id
FROM products p
INNER JOIN orders o ON p.product_id = o.product_id
WHERE o.order_date = '2024-08-20';

To list all products To list all orders To list product names and order IDs for orders placed on '2024-08-20'To list orders placed on any date

This query performs an INNER JOIN between the products and orders tables, filtered by the specified order date, and returns the product names and order IDs.

Q17

Single Choice

In an ORACLE SQL query, what would be the result of using an INNER JOIN with additional conditions in the WHERE clause?

The JOIN will occur before the WHERE conditions are applied The WHERE conditions will be applied before the JOIN The query will return all rows, ignoring the conditionsThe query will return an error

In Oracle SQL, the INNER JOIN operation is performed first, followed by the application of conditions in the WHERE clause to filter the results.

Q18

Single Choice

Given the following ORACLE SQL query:What will this query return?

SQL Code

SELECT e.employee_id, e.first_name, e.last_name, d.department_name
FROM employees e
INNER JOIN departments d ON e.department_id = d.department_id
WHERE d.department_name = 'Sales';

All employees and their department names Only employees from the Sales department Only the department namesEmployees with department IDs that do not match

This query returns only the employees who work in the 'Sales' department by applying the condition in the WHERE clause after performing the INNER JOIN.

Q19

Single Choice

Which of the following scenarios best describes when to use an INNER JOIN in ORACLE SQL?

When you need to combine all rows from two tables regardless of matching values When you need to find matching rows between two tables and only return those rows When you need to return all rows from the first table and matching rows from the second tableWhen you need to delete rows from one table based on matching values in another table

An INNER JOIN is used to combine rows from two tables where there is a match between the specified columns.

Q20

Single Choice

Given the following ORACLE SQL query: What does this query accomplish?

SQL Code

SELECT e.employee_id, e.first_name, p.project_name
FROM employees e
INNER JOIN project_assignments pa ON e.employee_id = pa.employee_id
INNER JOIN projects p ON pa.project_id = p.project_id
WHERE p.start_date > '2024-01-01';

Lists all employees and their projects, regardless of start date Lists employees and their projects that started after '2024-01-01' Lists only projects that started before '2024-01-01'Lists all projects regardless of employee assignments

This query uses multiple INNER JOINs to combine the employees, project_assignments, and projects tables, filtering the results to include only projects that started after the specified date.

Q21

Multiple Choice

Which SQL code snippet correctly demonstrates an INNER JOIN to combine employee and department data in Oracle?

SQL Code

SELECT e.employee_id, e.first_name, d.department_name
FROM employees e
INNER JOIN departments d ON e.department_id = d.department_id;

SELECT e.employee_id, e.first_name, d.department_name
FROM employees e
JOIN departments d ON e.department_id = d.department_id;

SELECT e.employee_id, d.department_name
FROM employees e
INNER JOIN departments d ON e.department_id = d.department_id;

SELECT e.employee_id, e.first_name, d.department_name FROM employees e INNER JOIN departments d ON e.department_id = d.department_id; SELECT e.employee_id, e.first_name, d.department_name FROM employees e JOIN departments d ON e.department_id = d.department_id; SELECT e.employee_id, d.department_name FROM employees e INNER JOIN departments d ON e.department_id = d.department_id;SELECT e.employee_id, d.department_name FROM employees e, departments d WHERE e.department_id = d.department_id;

Options A, B, and C correctly use INNER JOIN to combine employee and department data. Option D is incorrect because it does not use the JOIN correctly.

Q22

Multiple Choice

Which SQL code snippet uses INNER JOIN to retrieve orders and customers where the order amount exceeds $1000 in Oracle?

SQL Code

SELECT o.order_id, c.customer_name, o.order_amount
FROM orders o
INNER JOIN customers c ON o.customer_id = c.customer_id
WHERE o.order_amount > 1000;

SELECT o.order_id, c.customer_name, o.order_amount
FROM orders o
JOIN customers c ON o.customer_id = c.customer_id
WHERE o.order_amount > 1000;

SELECT o.order_id, o.order_amount, c.customer_name
FROM orders o
INNER JOIN customers c ON o.customer_id = c.customer_id
WHERE o.order_amount > 1000;

SELECT o.order_id, c.customer_name, o.order_amount FROM orders o INNER JOIN customers c ON o.customer_id = c.customer_id WHERE o.order_amount > 1000; SELECT o.order_id, c.customer_name, o.order_amount FROM orders o JOIN customers c ON o.customer_id = c.customer_id WHERE o.order_amount > 1000; SELECT o.order_id, o.order_amount, c.customer_name FROM orders o INNER JOIN customers c ON o.customer_id = c.customer_id WHERE o.order_amount > 1000;SELECT o.order_id, o.order_amount FROM orders o WHERE o.order_amount > 1000;

Options A, B, and C correctly use INNER JOIN to retrieve orders and customers where the order amount exceeds $1000. Option D is incorrect because it does not join the tables correctly.

Q23

Multiple Choice

Which SQL code snippet demonstrates an INNER JOIN to find employees who work in a specific location in Oracle?

SQL Code

SELECT e.employee_id, e.first_name, l.city
FROM employees e
INNER JOIN departments d ON e.department_id = d.department_id
INNER JOIN locations l ON d.location_id = l.location_id
WHERE l.city = 'New York';

SELECT e.employee_id, e.first_name, l.city
FROM employees e
JOIN departments d ON e.department_id = d.department_id
JOIN locations l ON d.location_id = l.location_id
WHERE l.city = 'New York';

SELECT e.employee_id, l.city
FROM employees e
INNER JOIN departments d ON e.department_id = d.department_id
INNER JOIN locations l ON d.location_id = l.location_id
WHERE l.city = 'New York';

SELECT e.employee_id, e.first_name, l.city FROM employees e INNER JOIN departments d ON e.department_id = d.department_id INNER JOIN locations l ON d.location_id = l.location_id WHERE l.city = 'New York'; SELECT e.employee_id, e.first_name, l.city FROM employees e JOIN departments d ON e.department_id = d.department_id JOIN locations l ON d.location_id = l.location_id WHERE l.city = 'New York'; SELECT e.employee_id, l.city FROM employees e INNER JOIN departments d ON e.department_id = d.department_id INNER JOIN locations l ON d.location_id = l.location_id WHERE l.city = 'New York';SELECT e.employee_id, l.city FROM employees e JOIN locations l ON e.location_id = l.location_id WHERE l.city = 'New York';

Options A, B, and C correctly demonstrate an INNER JOIN to find employees who work in a specific location. Option D is incorrect because it does not join the tables correctly.

Q24

Multiple Choice

Which SQL code snippet uses an INNER JOIN to calculate the total sales for each product category in Oracle?

SQL Code

SELECT c.category_name, SUM(o.order_amount) AS total_sales
FROM categories c
INNER JOIN products p ON c.category_id = p.category_id
INNER JOIN orders o ON p.product_id = o.product_id
GROUP BY c.category_name;

SELECT c.category_name, SUM(o.order_amount) AS total_sales
FROM categories c
JOIN products p ON c.category_id = p.category_id
JOIN orders o ON p.product_id = o.product_id
GROUP BY c.category_name;

SELECT c.category_name, SUM(o.order_amount) AS total_sales
FROM categories c
INNER JOIN products p ON c.category_id = p.category_id
INNER JOIN orders o ON p.product_id = o.product_id
WHERE o.order_amount > 0
GROUP BY c.category_name;

SELECT c.category_name, SUM(o.order_amount) AS total_sales FROM categories c INNER JOIN products p ON c.category_id = p.category_id INNER JOIN orders o ON p.product_id = o.product_id GROUP BY c.category_name; SELECT c.category_name, SUM(o.order_amount) AS total_sales FROM categories c JOIN products p ON c.category_id = p.category_id JOIN orders o ON p.product_id = o.product_id GROUP BY c.category_name; SELECT c.category_name, SUM(o.order_amount) AS total_sales FROM categories c INNER JOIN products p ON c.category_id = p.category_id INNER JOIN orders o ON p.product_id = o.product_id WHERE o.order_amount > 0 GROUP BY c.category_name;SELECT c.category_name, o.order_amount FROM categories c JOIN products p ON c.category_id = p.category_id JOIN orders o ON p.product_id = o.product_id;

Options A, B, and C correctly use an INNER JOIN to calculate the total sales for each product category. Option D is incorrect because it does not join the tables correctly.

Q25

Multiple Choice

Which SQL code snippet demonstrates an INNER JOIN to list all employees along with their managers' names in Oracle?

SQL Code

SELECT e1.employee_id, e1.first_name AS employee_name, e2.first_name AS manager_name
FROM employees e1
INNER JOIN employees e2 ON e1.manager_id = e2.employee_id;

SELECT e.employee_id, e.first_name, m.first_name AS manager_name
FROM employees e
INNER JOIN employees m ON e.manager_id = m.employee_id;

SELECT e.employee_id, e.first_name AS employee_name, m.first_name AS manager_name
FROM employees e
JOIN employees m ON e.manager_id = m.employee_id;

SELECT e1.employee_id, e1.first_name AS employee_name, e2.first_name AS manager_name FROM employees e1 INNER JOIN employees e2 ON e1.manager_id = e2.employee_id; SELECT e.employee_id, e.first_name, m.first_name AS manager_name FROM employees e INNER JOIN employees m ON e.manager_id = m.employee_id; SELECT e.employee_id, e.first_name AS employee_name, m.first_name AS manager_name FROM employees e JOIN employees m ON e.manager_id = m.employee_id;SELECT e.employee_id, e.first_name FROM employees e WHERE e.manager_id IS NOT NULL;

Options A, B, and C correctly use an INNER JOIN to list all employees along with their managers' names. Option D is incorrect because it does not join the employees table correctly.

Q26

Multiple Choice

Which SQL code snippet demonstrates advanced use of INNER JOIN to retrieve products that have been ordered in the last month in Oracle?

SQL Code

SELECT p.product_id, p.product_name, o.order_date
FROM products p
INNER JOIN orders o ON p.product_id = o.product_id
WHERE o.order_date >= ADD_MONTHS(SYSDATE, -1);

SELECT p.product_id, p.product_name, o.order_date
FROM products p
JOIN orders o ON p.product_id = o.product_id
WHERE o.order_date >= ADD_MONTHS(SYSDATE, -1);

SELECT p.product_id, p.product_name, o.order_date
FROM products p
INNER JOIN orders o ON p.product_id = o.product_id
WHERE o.order_date >= ADD_MONTHS(SYSDATE, -1)
ORDER BY o.order_date DESC;

SELECT p.product_id, p.product_name, o.order_date FROM products p INNER JOIN orders o ON p.product_id = o.product_id WHERE o.order_date >= ADD_MONTHS(SYSDATE, -1); SELECT p.product_id, p.product_name, o.order_date FROM products p JOIN orders o ON p.product_id = o.product_id WHERE o.order_date >= ADD_MONTHS(SYSDATE, -1); SELECT p.product_id, p.product_name, o.order_date FROM products p INNER JOIN orders o ON p.product_id = o.product_id WHERE o.order_date >= ADD_MONTHS(SYSDATE, -1) ORDER BY o.order_date DESC;SELECT p.product_id, o.order_date FROM products p WHERE o.order_date >= ADD_MONTHS(SYSDATE, -1);

Options A, B, and C correctly demonstrate advanced use of INNER JOIN to retrieve products ordered in the last month. Option D is incorrect because it does not join the tables correctly.

Q27

Multiple Choice

Which SQL code snippet uses INNER JOIN to find customers who have placed more than one order in Oracle?

SQL Code

SELECT c.customer_id, c.customer_name, COUNT(o.order_id) AS num_orders
FROM customers c
INNER JOIN orders o ON c.customer_id = o.customer_id
GROUP BY c.customer_id, c.customer_name
HAVING COUNT(o.order_id) > 1;

SELECT c.customer_id, c.customer_name, COUNT(o.order_id) AS num_orders
FROM customers c
JOIN orders o ON c.customer_id = o.customer_id
GROUP BY c.customer_id, c.customer_name
HAVING COUNT(o.order_id) > 1;

SELECT c.customer_id, c.customer_name, COUNT(o.order_id) AS num_orders
FROM customers c
INNER JOIN orders o ON c.customer_id = o.customer_id
GROUP BY c.customer_id
HAVING COUNT(o.order_id) > 1;

SELECT c.customer_id, c.customer_name, COUNT(o.order_id) AS num_orders FROM customers c INNER JOIN orders o ON c.customer_id = o.customer_id GROUP BY c.customer_id, c.customer_name HAVING COUNT(o.order_id) > 1; SELECT c.customer_id, c.customer_name, COUNT(o.order_id) AS num_orders FROM customers c JOIN orders o ON c.customer_id = o.customer_id GROUP BY c.customer_id, c.customer_name HAVING COUNT(o.order_id) > 1; SELECT c.customer_id, c.customer_name, COUNT(o.order_id) AS num_orders FROM customers c INNER JOIN orders o ON c.customer_id = o.customer_id GROUP BY c.customer_id HAVING COUNT(o.order_id) > 1;SELECT c.customer_id, COUNT(o.order_id) AS num_orders FROM customers c JOIN orders o ON c.customer_id = o.customer_id HAVING COUNT(o.order_id) > 1;

Options A, B, and C correctly use INNER JOIN to find customers who have placed more than one order. Option D is incorrect because it does not group by customer_name.

Q28

Multiple Choice

Which SQL code snippet demonstrates the use of INNER JOIN to list all orders along with the product name and category in Oracle?

SQL Code

SELECT o.order_id, p.product_name, c.category_name
FROM orders o
INNER JOIN products p ON o.product_id = p.product_id
INNER JOIN categories c ON p.category_id = c.category_id;

SELECT o.order_id, p.product_name, c.category_name
FROM orders o
JOIN products p ON o.product_id = p.product_id
JOIN categories c ON p.category_id = c.category_id;

SELECT o.order_id, p.product_name, c.category_name
FROM orders o
INNER JOIN products p ON o.product_id = p.product_id
INNER JOIN categories c ON p.category_id = c.category_id
WHERE o.order_date >= SYSDATE - 30;

SELECT o.order_id, p.product_name, c.category_name FROM orders o INNER JOIN products p ON o.product_id = p.product_id INNER JOIN categories c ON p.category_id = c.category_id; SELECT o.order_id, p.product_name, c.category_name FROM orders o JOIN products p ON o.product_id = p.product_id JOIN categories c ON p.category_id = c.category_id; SELECT o.order_id, p.product_name, c.category_name FROM orders o INNER JOIN products p ON o.product_id = p.product_id INNER JOIN categories c ON p.category_id = c.category_id WHERE o.order_date >= SYSDATE - 30;SELECT o.order_id, p.product_name FROM orders o JOIN products p ON o.product_id = p.product_id;

Options A, B, and C correctly demonstrate the use of INNER JOIN to list all orders along with the product name and category. Option D is incorrect because it does not include the category_name in the SELECT statement.

Q29

Multiple Choice

Which SQL code snippet demonstrates advanced use of INNER JOIN to calculate the average order amount for each customer in Oracle?

SQL Code

SELECT c.customer_id, c.customer_name, AVG(o.order_amount) AS avg_order_amount
FROM customers c
INNER JOIN orders o ON c.customer_id = o.customer_id
GROUP BY c.customer_id, c.customer_name;

SELECT c.customer_id, c.customer_name, AVG(o.order_amount) AS avg_order_amount
FROM customers c
JOIN orders o ON c.customer_id = o.customer_id
GROUP BY c.customer_id, c.customer_name;

SELECT c.customer_id, c.customer_name, AVG(o.order_amount) AS avg_order_amount
FROM customers c
INNER JOIN orders o ON c.customer_id = o.customer_id
WHERE o.order_amount > 0
GROUP BY c.customer_id, c.customer_name;

SELECT c.customer_id, c.customer_name, AVG(o.order_amount) AS avg_order_amount FROM customers c INNER JOIN orders o ON c.customer_id = o.customer_id GROUP BY c.customer_id, c.customer_name; SELECT c.customer_id, c.customer_name, AVG(o.order_amount) AS avg_order_amount FROM customers c JOIN orders o ON c.customer_id = o.customer_id GROUP BY c.customer_id, c.customer_name; SELECT c.customer_id, c.customer_name, AVG(o.order_amount) AS avg_order_amount FROM customers c INNER JOIN orders o ON c.customer_id = o.customer_id WHERE o.order_amount > 0 GROUP BY c.customer_id, c.customer_name;SELECT c.customer_id, AVG(o.order_amount) AS avg_order_amount FROM customers c JOIN orders o ON c.customer_id = o.customer_id GROUP BY c.customer_id;

Options A, B, and C correctly demonstrate advanced use of INNER JOIN to calculate the average order amount for each customer. Option D is incorrect because it does not group by customer_name.

Q30

Multiple Choice

Which SQL code snippet demonstrates certification-level use of INNER JOIN to generate a sales report by region in Oracle?

SQL Code

SELECT r.region_name, SUM(o.order_amount) AS total_sales
FROM regions r
INNER JOIN customers c ON r.region_id = c.region_id
INNER JOIN orders o ON c.customer_id = o.customer_id
GROUP BY r.region_name;

SELECT r.region_name, SUM(o.order_amount) AS total_sales
FROM regions r
JOIN customers c ON r.region_id = c.region_id
JOIN orders o ON c.customer_id = o.customer_id
GROUP BY r.region_name;

SELECT r.region_name, SUM(o.order_amount) AS total_sales
FROM regions r
INNER JOIN customers c ON r.region_id = c.region_id
INNER JOIN orders o ON c.customer_id = o.customer_id
WHERE o.order_date >= SYSDATE - 365
GROUP BY r.region_name;

SELECT r.region_name, SUM(o.order_amount) AS total_sales FROM regions r INNER JOIN customers c ON r.region_id = c.region_id INNER JOIN orders o ON c.customer_id = o.customer_id GROUP BY r.region_name; SELECT r.region_name, SUM(o.order_amount) AS total_sales FROM regions r JOIN customers c ON r.region_id = c.region_id JOIN orders o ON c.customer_id = o.customer_id GROUP BY r.region_name; SELECT r.region_name, SUM(o.order_amount) AS total_sales FROM regions r INNER JOIN customers c ON r.region_id = c.region_id INNER JOIN orders o ON c.customer_id = o.customer_id WHERE o.order_date >= SYSDATE - 365 GROUP BY r.region_name;SELECT r.region_name, o.order_amount FROM regions r JOIN customers c ON r.region_id = c.region_id JOIN orders o ON c.customer_id = o.customer_id;

Options A, B, and C correctly demonstrate certification-level use of INNER JOIN to generate a sales report by region. Option D is incorrect because it does not group by region_name.

Oracle Database Quiz Questions