The following data definition defines an organization's employee hierarchy.
An employee is a manager if any other employee has their managerId set to this employee's id. That means John is a manager if at least one other employee has their managerId set to John's id.
TABLE employees id INTEGER NOT NULL PRIMARY KEY managerId INTEGER REFERENCES employees(id) name VARCHAR(30) NOT NULL
Write a query that selects only the names of employees who are not managers.
See the example case for more details.
- Example case: Wrong answer
- No managers: Wrong answer
- Workers have managers: Wrong answer
- Managers have managers: Wrong answer