The staff table stores every person including their manager (viamanager_id). The CEO has manager_id = NULL.
Write a SQL query that returns each non-CEO employee's name alongside their
manager's name, ordered by employee name.
Table: `staff`
| id | name | manager_id |
|---|---|---|
| 1 | CEO | NULL |
| 2 | Alice | 1 |
| 3 | Bob | 1 |
| 4 | Carol | 2 |
| 5 | Dave | 2 |
| 6 | Eve | 3 |
Expected output (columns: employee, manager)
Alice|CEO
Bob|CEO
Carol|Alice
Dave|Alice
Eve|BobA self-join joins a table to itself using two aliases to treat rows as
different "roles" (employee vs manager).
Sample tests