-- Creating a sample table
CREATE TABLE employees (
id INT,
name VARCHAR(50)
);
-- Inserting data into the table
INSERT INTO employees (id, name) VALUES (1, 'John');
INSERT INTO employees (id, name) VALUES (2, 'Jane');
INSERT INTO employees (id, name) VALUES (3, 'Michael');
INSERT INTO employees (id, name) VALUES (4, 'Emily');
-- Query to get a union of two sets
SELECT name FROM employees
UNION
SELECT name FROM other_employees;
-- Query to get an intersection of two sets
SELECT name FROM employees
INTERSECT
SELECT name FROM other_employees;
-- Query to get a difference between two sets
SELECT name FROM employees
EXCEPT
SELECT name FROM other_employees;
-- Query to get a Cartesian product of two sets
SELECT *
FROM employees, departments;
-- Query to get the number of elements in a set
SELECT COUNT(*) AS set_size FROM employees;
-- Query to check if a value is present in a set
SELECT COUNT(*) FROM employees
WHERE id = 2;