Database Reference
In-Depth Information
A key concept to be kept in mind when aligning relationships with use cases is the
naming strategy for your relationship types. The general recommendation is to
use as few generic names such as
HAS_A
or
IS_PART_OF
as possible, but to be more
speciicinthesenamingefforts.
Look for n-ary relationships
Sometimes, youwillindthattheirstreadingofyouruserstorieswillnotyield
optimal results. Obviously, there can be many reasons for this, but this is often because
there are some
hidden
modelelementsinthesestoriesthatwedidnotspotatirst.
One of the cases where we often see this is when dealing with the so-called n-ary
relationships. These types of relationships are often hidden in the model when we
want to associate more than two things; in some cases, the natural and convenient
way to represent certain concepts is to use relations to link a concept to more than
just one concept. These relations are called n-ary relations because they can serve
more than two (in fact,
n
) things or concepts. It is a very common modeling pattern.
When we discover these types of relationships in a graph model, this typically means
that there's an additional node to discover that we have split out a new entity.
Transforming n-ary relationships into nodes
This is exactly what we have done in the preceding example.
