Association between two entries in SQL table

Question

Imagine you have a database table that stores a list of people. You want to establish a relationship between peoples, i.e., person I is friend with person J.

I suppo

Answer 1

You might also want to establish the type of reletionship. In this case you'd ideally use 2 tables, RelationshipTypes and Relationships. The unique key could be on all 3 Relationship fields.

Relationships
  PersonId
  RelatedPersonId
  RelationshipTypeId

RelationsShipTypes
  Id
  Name