How do you remove all employees in departments with no managers assigned?

Short answer: DELETE with WHERE DepartmentId IN (departments where ManagerId IS NULL) or use JOIN. Preview with SELECT first.

Sample solution

DELETE e
FROM Employees e
INNER JOIN Departments d ON d.DepartmentId = e.DepartmentId
WHERE d.ManagerId IS NULL;

In interviews, always say you would run SELECT with the same FROM/WHERE before DELETE.