title: Get the names of all employees who never took a vacation day
body: <p>Table for Employee and DaysTaken </p>
  
  <p><a href="https://i.stack.imgur.com/uYEkY.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/uYEkY.png" alt="enter image description here"></a></p>
  
  <p>Hi, i m facing a problem that a employee'John Smith' take 'sick day' and 'vacation'. 
  This is my current answer</p>
  
  <pre><code>SELECT DISTINCT CONCAT(FirstName, ' ', MiddleName, ' ',  LastName) AS 'CompleteName' from Employee
  RIGHT JOIN DaysTaken ON
  Employee.EmployeeID =
  DaysTaken.EmployeeID
  WHERE (DaysTaken.vacationtype = 'sick day')
  </code></pre>