Can there be in 1 table, two identical others?

Question

SQL

Can there be in 1 table two identical others?
for example, I have 10 elements in the ONE table, the
second table SHIP has id / ONE_ID1/ONE_ID2/count in it,
the ratio of each id to another != itself.
How to implement it?

Answer 1

In the same table, different records can have the same foreign keys. BUT they (in theory) should have different primary keys, after all, these are different phones, and they should refer to a single record of another table where the owners are collected. After all, in the general case, a single person owns a thing.