table runners
| id | name |
| 1 | John Doe |
| 2 | Jane Doe |
| 3 | Alice Jones |
| 4 | Bobby Louis |
| 5 | Lisa Romero |
table races
| id | event | winner_id |
| 1 | 100 meter dash | 2 |
| 2 | 500 meter dash | 3 |
| 3 | crosscountry | 2 |
| 4 | triathalon | NULL |
Output of the query below?
SELECT * FROM runners WHERE id NOT IN (SELECT winner_id FROM races)
"Their is no row selected due to 'null' in races table" Please explain the reason of this.
Thanks in advance.