gistfile1.txt

--The following data definition defines an organization's employee hierarchy.

--An employee is a manager if any other employee has their managerId set to the first employees id. An employee who is a manager may or may not also have a manager.

--TABLE employees
--  id INTEGER NOT NULL PRIMARY KEY
--  managerId INTEGER REFERENCES employees(id)
--  name VARCHAR(30) NOT NULL
--Write a query that selects the names of employees who are not managers.
--https://www.testdome.com/questions/sql/workers/13562?visibility=1&skillId=17

-- Write only the SQL statement that solves the problem and nothing else.
select name from employees where id not in (
  select managerId from employees where managerId is not null
)