What SQL query should I perform to get the result set expected, giving the first element of the chain (2) as input data, or any of them ?
table name: changes
+----+---------------+---------------+
| id | new_record_id | old_record_id |
+----+---------------+---------------+
| 1| 4| 2|
| -- non relevant data -- |
| 6| 7| 4|
| -- non relevant data -- |
| 11| 13| 7|
| 12| 14| 13|
| -- non relevant data -- |
| 31| 20| 14|
+----+---------------+---------------+
Result set expected:
+--+
| 2|
| 4|
| 7|
|13|
|14|
|20|
+--+
I know I should consider change my data model, but: What if I couldn't?
Thank you in advance!