Test Your PostgreSQL '>' and '<' Operators Knowledge with This Quiz

Progress

True / False

In PostgreSQL, the > operator is used to compare if one value is greater than another.

True False

The > operator checks if the value on the left is greater than the value on the right.

True / False

In PostgreSQL, the < operator is used to compare if one value is less than another.

True False

The < operator checks if the value on the left is less than the value on the right.

True / False

In PostgreSQL, the expression 5 > 3 evaluates to FALSE.

True False

The expression 5 > 3 evaluates to TRUE because 5 is greater than 3.

True / False

In PostgreSQL, the > and < operators can be used to compare both numeric and date values.

True False

The > and < operators can be used to compare numeric, date, and other types of values in PostgreSQL.

True / False

In PostgreSQL, NULL > 0 and NULL < 0 both evaluate to FALSE.

True False

In PostgreSQL, any comparison with NULL results in NULL, which is not TRUE or FALSE but unknown.

True / False

In PostgreSQL, the query SELECT * FROM table WHERE column > 100 returns rows where the column value is greater than 100.

True False

The query filters rows where the value in column is greater than 100.

True / False

In PostgreSQL, the > and < operators can be combined with the BETWEEN operator to check for a range of values.

True False

While the BETWEEN operator is often used for range checks, > and < can also be used to define custom range conditions.

True / False

In PostgreSQL, the expression column1 > column2 will always evaluate to TRUE if column1 and column2 contain the same values.

True False

If column1 and column2 contain the same values, the expression column1 > column2 will evaluate to FALSE.

True / False

In PostgreSQL, using > or < operators in ORDER BY clauses sorts the results based on the specified condition.

True False

The ORDER BY clause uses ASC or DESC for sorting, not > or < operators. However, these operators are used within WHERE clauses for filtering.

Q10

True / False

In PostgreSQL, using the > operator in an indexed column's query condition can improve query performance by leveraging the index.

True False

If a column is indexed, using the > operator in query conditions can improve performance as the index helps in quickly locating the relevant rows.

Q11

Single Choice

What will be the result of the following PostgreSQL query?

SQL Code

SELECT 10 > 5;

True False NULLNULL

The > operator checks if the left operand is greater than the right operand. In this case, 10 > 5 is true.

Q12

Single Choice

What is the output of the following PostgreSQL query?

SQL Code

SELECT 3 < 7;

True False NULLNULL

The < operator checks if the left operand is less than the right operand. In this case, 3 < 7 is true.

Q13

Single Choice

Which of the following is the correct PostgreSQL query to check if 20 is less than 15?

SELECT 20 < 15; SELECT 20 > 15; SELECT 20 == 15;SELECT 20 >= 15;

The correct operator to check if 20 is less than 15 is <.

Q14

Single Choice

What will the following PostgreSQL query return?

SQL Code

SELECT 'apple' < 'banana';

True False NULLNULL

In PostgreSQL, strings can be compared lexicographically. Here, 'apple' is less than 'banana' because it comes first in alphabetical order.

Q15

Single Choice

Given the following PostgreSQL query, what will be the result?

SQL Code

SELECT 5 > (SELECT COUNT(*) FROM users);

True False NULLNULL

The query checks if 5 is greater than the number of rows in the users table. The result depends on the actual count.

Q16

Single Choice

What is the output of the following PostgreSQL query?

SQL Code

SELECT 15 < 15;

True False NULLNULL

The < operator checks if the left operand is less than the right operand. Since 15 is not less than 15, the result is false.

Q17

Single Choice

What does the following PostgreSQL query return?

SQL Code

SELECT 100 > ALL (SELECT age FROM employees);

True False NULLNULL

The > ALL operator checks if 100 is greater than all values returned by the subquery.

Q18

Single Choice

What will the following PostgreSQL query return?

SQL Code

SELECT salary < ANY (SELECT salary FROM employees WHERE department = 'Sales');

True False NULLNULL

The < ANY operator checks if the salary is less than any of the salaries in the Sales department.

Q19

Single Choice

In PostgreSQL, what does the following query check?

SQL Code

SELECT age > (SELECT AVG(age) FROM employees);

If the age is greater than the average age of employees. If the age is less than the average age of employees. If the age is equal to the average age of employees.If the age is NULL.

The query checks if the age is greater than the average age of all employees.

Q20

Single Choice

Consider the following PostgreSQL query:

SQL Code

SELECT employee_id FROM employees WHERE salary > (SELECT MAX(salary) FROM employees WHERE department = 'HR');
What is the purpose of this query?

To find employees who earn more than the highest-paid employee in the HR department. To find employees who earn less than the lowest-paid employee in the HR department. To find employees who earn exactly as much as the highest-paid employee in the HR department.To find employees who earn more than the average salary in the HR department.

The query compares the salary of each employee to the maximum salary in the HR department, returning those who earn more.

Q21

Multiple Choice

Identify the SQL scripts that correctly use the '>' and '<' operators to filter numeric values in PostgreSQL.

SELECT * FROM products WHERE price > 50 AND price < 100; SELECT * FROM products WHERE price > 50 OR price < 100; SELECT * FROM products WHERE price > 50 AND price <= 100;SELECT * FROM products WHERE price >= 50 AND price < 100;

The '>' and '<' operators are used to filter rows based on numeric comparisons. The correct scripts will demonstrate how to use both operators effectively in PostgreSQL.

Q22

Multiple Choice

Select the SQL scripts that correctly use the '>' and '<' operators with dates in PostgreSQL.

SELECT * FROM orders WHERE order_date > '2023-01-01' AND order_date < '2023-12-31'; SELECT * FROM orders WHERE order_date >= '2023-01-01' AND order_date <= '2023-12-31'; SELECT * FROM orders WHERE order_date > '2023-01-01' OR order_date < '2023-12-31';SELECT * FROM orders WHERE order_date >= '2023-01-01' AND order_date < '2023-12-31';

Using the '>' and '<' operators with dates allows you to filter rows based on date ranges. The correct scripts will demonstrate how to use these operators with date comparisons in PostgreSQL.

Q23

Multiple Choice

Determine the SQL scripts that correctly use the '>' and '<' operators with text values in PostgreSQL.

SELECT * FROM customers WHERE last_name > 'M' AND last_name < 'Z'; SELECT * FROM customers WHERE last_name > 'M' OR last_name < 'Z'; SELECT * FROM customers WHERE last_name >= 'M' AND last_name <= 'Z';SELECT * FROM customers WHERE last_name > 'M' AND last_name <= 'Z';

The '>' and '<' operators can be used with text values to filter rows based on alphabetical order. The correct scripts will demonstrate how to use these operators with text comparisons in PostgreSQL.

Q24

Multiple Choice

Identify the SQL scripts that correctly use the '>' and '<' operators with JOINs in PostgreSQL.

SELECT * FROM employees e JOIN departments d ON e.department_id = d.department_id WHERE e.salary > 60000 AND d.budget < 500000; SELECT * FROM employees WHERE salary > 60000 AND department_id IN (SELECT department_id FROM departments WHERE budget < 500000); SELECT * FROM employees WHERE salary > 60000 AND EXISTS (SELECT 1 FROM departments WHERE budget < 500000 AND departments.department_id = employees.department_id);SELECT * FROM employees e JOIN departments d ON e.department_id = d.department_id WHERE e.salary > 60000 OR d.budget < 500000;

The '>' and '<' operators can be used with JOINs to filter rows based on conditions in related tables. The correct scripts will demonstrate how to use these operators with JOINs in PostgreSQL.

Q25

Multiple Choice

Select the SQL scripts that correctly use the '>' and '<' operators with aggregate functions in PostgreSQL.

SELECT department_id FROM employees GROUP BY department_id HAVING AVG(salary) > 70000 AND AVG(salary) < 100000; SELECT department_id FROM employees GROUP BY department_id HAVING AVG(salary) > 70000 OR AVG(salary) < 100000; SELECT department_id FROM employees GROUP BY department_id HAVING AVG(salary) >= 70000 AND AVG(salary) <= 100000;SELECT department_id FROM employees GROUP BY department_id HAVING AVG(salary) > 70000 AND AVG(salary) <= 100000;

The '>' and '<' operators can be used with aggregate functions to filter groups based on calculated values. The correct scripts will demonstrate how to use these operators with aggregate functions in PostgreSQL.

Q26

Multiple Choice

Determine the SQL scripts that correctly use the '>' and '<' operators with window functions in PostgreSQL.

SELECT employee_id, salary, RANK() OVER (ORDER BY salary DESC) AS rank FROM employees WHERE salary > 80000 AND salary < 120000; SELECT employee_id, salary, DENSE_RANK() OVER (ORDER BY salary DESC) AS rank FROM employees WHERE salary > 80000 AND salary <= 120000; SELECT employee_id, salary, ROW_NUMBER() OVER (ORDER BY salary DESC) AS rank FROM employees WHERE salary >= 80000 AND salary < 120000;SELECT employee_id, salary, RANK() OVER (ORDER BY salary DESC) AS rank FROM employees WHERE salary > 80000 OR salary < 120000;

The '>' and '<' operators can be used with window functions to filter and rank results based on specific conditions. The correct scripts will demonstrate how to use these operators with window functions in PostgreSQL.

Q27

Multiple Choice

Identify the SQL scripts that correctly use the '>' and '<' operators with UNION in PostgreSQL.

SELECT * FROM orders WHERE order_amount > 500 AND order_amount < 1000 UNION SELECT * FROM backorders WHERE order_amount > 500 AND order_amount < 1000; SELECT * FROM orders WHERE order_amount > 500 OR order_amount < 1000 UNION SELECT * FROM backorders WHERE order_amount > 500 OR order_amount < 1000; SELECT * FROM orders WHERE order_amount > 500 AND order_amount <= 1000 UNION ALL SELECT * FROM backorders WHERE order_amount > 500 AND order_amount < 1000;SELECT * FROM orders WHERE order_amount >= 500 AND order_amount < 1000 UNION SELECT * FROM backorders WHERE order_amount > 500 AND order_amount < 1000;

The '>' and '<' operators can be used with UNION to filter and combine results from multiple tables based on specific conditions. The correct scripts will demonstrate how to use these operators with UNION in PostgreSQL.

Q28

Multiple Choice

Determine the SQL scripts that correctly use the '>' and '<' operators with EXISTS in PostgreSQL.

SELECT * FROM employees WHERE EXISTS (SELECT 1 FROM departments WHERE departments.department_id = employees.department_id) AND salary > 70000; SELECT * FROM employees WHERE salary > 70000 AND EXISTS (SELECT 1 FROM departments WHERE departments.department_id = employees.department_id); SELECT * FROM employees WHERE EXISTS (SELECT 1 FROM departments WHERE departments.department_id = employees.department_id AND salary > 70000);SELECT * FROM employees WHERE department_id = NULL AND salary > 70000;

The '>' and '<' operators can be combined with EXISTS to filter rows based on conditions in related tables. The correct scripts will demonstrate how to use these operators with EXISTS in PostgreSQL.

Q29

Multiple Choice

Identify the SQL scripts that correctly use the '>' and '<' operators with DISTINCT in PostgreSQL.

SELECT DISTINCT product_id FROM sales WHERE quantity_sold > 50 AND quantity_sold < 200; SELECT DISTINCT product_id FROM sales WHERE quantity_sold > 50 OR quantity_sold < 200; SELECT DISTINCT product_id FROM sales WHERE quantity_sold >= 50 AND quantity_sold <= 200;SELECT DISTINCT product_id FROM sales WHERE quantity_sold > 50 AND quantity_sold <= 200;

The '>' and '<' operators can be used with DISTINCT to filter unique rows based on specific conditions. The correct scripts will demonstrate how to use these operators with DISTINCT in PostgreSQL.

Q30

Multiple Choice

Determine the SQL scripts that correctly use the '>' and '<' operators with LIMIT OFFSET in PostgreSQL.

SELECT * FROM products WHERE stock_quantity > 100 AND stock_quantity < 500 ORDER BY product_id LIMIT 10 OFFSET 0; SELECT * FROM products WHERE stock_quantity > 100 OR stock_quantity < 500 ORDER BY product_id LIMIT 10; SELECT * FROM products WHERE stock_quantity > 100 AND stock_quantity <= 500 ORDER BY product_id LIMIT 10 OFFSET 5;SELECT * FROM products WHERE stock_quantity >= 100 AND stock_quantity < 500 ORDER BY product_id LIMIT 10 OFFSET 0;

The '>' and '<' operators can be used with LIMIT OFFSET to filter and paginate results based on multiple conditions. The correct scripts will demonstrate how to use these operators with LIMIT OFFSET in PostgreSQL.

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