SELECT date, closing_price,
       LEAD(closing_price) OVER (ORDER BY date) AS next_day_price,
       LEAD(closing_price) OVER (ORDER BY date) - closing_price AS price_change
FROM stock_prices;
-- Output:
date        | closing_price | next_day_price | price_change
------------|--------------|----------------|-------------
2024-01-01  | 150.25      | 152.50         | 2.25
2024-01-02  | 152.50      | 151.75         | -0.75
2024-01-03  | 151.75      | 153.00         | 1.25
2024-01-04  | 153.00      | 152.25         | -0.75
2024-01-05  | 152.25      | NULL           | NULL

SELECT sequence_id,
       CASE WHEN LEAD(sequence_id) OVER (ORDER BY sequence_id) - sequence_id > 1
            THEN 'Gap Found'
            ELSE 'No Gap'
       END AS sequence_check
FROM sequences;
-- Output:
sequence_id | sequence_check
------------|---------------
1           | No Gap
2           | No Gap
3           | Gap Found
6           | No Gap
7           | No Gap
8           | Gap Found
10          | No Gap

SELECT patient_name, appointment_date,
       LEAD(appointment_date, 1, 'No future appointment') OVER (PARTITION BY patient_id ORDER BY appointment_date)
       AS next_appointment
FROM appointments;
-- Output:
patient_name  | appointment_date | next_appointment
-------------|-----------------|------------------
John Smith    | 2024-01-15     | 2024-02-15
John Smith    | 2024-02-15     | 2024-03-15
John Smith    | 2024-03-15     | No future appointment
Maria Garcia  | 2024-01-20     | 2024-04-20
Maria Garcia  | 2024-04-20     | No future appointment
James Brown   | 2024-02-01     | 2024-02-15