title: Find hire date difference between two employees
body: <p>I have an employee table where the fields are:</p>
  
  <p><code>first_name, last_name, hire_date, salary, department_id, department_name</code>, and so on.</p>
  
  <p>I intend to find the hire date difference between <code>EMPLOYEE1 and EMPLOYEE2</code>, then <code>EMPLOYEE2 and EMPLOYEE3</code>, and so on.</p>
  
  <p>I have to write a query in sql to display the first name and hire date difference of employee</p>