ForeignKey Referencing Same Table

Question

There was an interview test in which below was the table and structure

 Table Person = id, name, dob, dod, mother_id, father_id
 Primary Key (id)
 Foreign Key mo         


        

Answer 1

The answer was already given by podiluska, just explaining how it works since it looks like you're new to MySql.

By giving an Alias to a table(like mother or father to the table person) you do something like a pseudo-table, that the MySql interprets as another table, so the join happens normally, just imagine there are 3 tables now. Person, Father and Mother, and they are all linked together by the join.