Recursive relationships in a database design

Question

How can we handled are recursive relationships in a database design? Describe briefly?

Answer 1

A recursive relationship is a relationship between entities of the same class, and is represented in the similar way as other relationships are. The rows of the tables can take two various roles, but. Some are parent rows, and the others are child rows. Furthermore, the table will contain both its own primary key and the foreign key which links back to the table itself. When a row has no parent, then the value of the foreign key column in which row will be null. If the row has a parent, then there should be a foreign key value in that row which corresponds to the primary key value of any other row in the table.