example_queries.py

-- Create the 'employees' table with appropriate data types
CREATE TABLE employees (
    employee_id INT PRIMARY KEY,
    first_name VARCHAR(20),
    last_name VARCHAR(25),
    email VARCHAR(25),
    phone_number VARCHAR(20),
    hire_date DATE,
    job_id VARCHAR(10),
    salary DECIMAL(8,2),
    commission_pct DECIMAL(2,2),
    manager_id INT,
    department_id INT
);

-- Create the 'job_history' table with appropriate data types
CREATE TABLE job_history (
    employee_id INT,
    start_date DATE,
    end_date DATE,
    job_id VARCHAR(10),
    department_id INT,
    PRIMARY KEY (employee_id, start_date)
);

-- Query to find employees without any job history and count occurrences of each job_id
SELECT e.job_id, COUNT(e.job_id) AS job_count
FROM employees e
LEFT JOIN job_history jh ON e.employee_id = jh.employee_id
WHERE jh.job_id IS NULL
GROUP BY e.job_id
ORDER BY e.job_id;