Retrieve Previous Employee Salary Using LAG

Question

Find the previous employee's salary using a window function.

Accepted Answer

```sql
SELECT 
    id, 
    name, 
    salary, 
    LAG(salary) OVER (ORDER BY id) AS previous_salary
FROM employees;
```

This query uses the `LAG()` window function to retrieve the salary value from the preceding row, ordered by the employee `id`, and displays it alongside the current salary.