Tag: unary relationship

N-ary relationship types

When we design a database, we draw an entity relationship diagram (ERD). It helps us understand what kind of information we want to store and what kind of relationships there are. It is imperative that this diagram is easy to read and understand.The number of entities in a relationship is the arity of this relationship. The aim of this article is to give some examples and show how big an impact the arity of relationships has on not only the readability of the diagram, but also the database itself.