How to find duplicate records in sql?

Question

SQL

It is not possible to create a query to search for reverse duplicates in the database.
There is a table let's call it list with fields id | id_to | id_from

1 | 10 | 30
2 | 99 | 72
3 | 60 | 84
4 | 70 | 66
5 | 80 | 37
6 | 30 | 10

I need to find element 6 as it is a duplicate of element 1.

Answer 1

JOIN tables with it according to the desired condition.