Self Join Employees Table for Dates

Question

Find employees who joined before their manager.

Accepted Answer

```sql
SELECT e.name 
FROM employees e
JOIN employees m ON e.manager_id = m.id
WHERE e.joined_at < m.joined_at;
```

This query performs a self-join on the "employees" table to compare the "joined_at" date of each employee with the "joined_at" date of their respective manager, returning the names of employees who joined earlier.