Data modeling in Neo4j - Neo4j in Action - page 25

• A person lives at an address .
• An underground station is connected to another underground sta-
tion on an underground line .
• A smartphone bundle includes a smartphone and a call allowance .
These patterns fit collections of facts:
• Peter lives at The Gables . Mary lives at 13 Acacia Avenue .
• Bank Station is connected to Moorgate Station . Bank Station and
Moorgate Station are both on the Northern Line .
• The light usage bundle includes a FictoPhone smartphone , and
150 minutes per month of mobile-to-mobile calls .
Once you have a consistent description of the data that will be stored in the database, you
can use this description to reason about the queries you'll put to that database in the future.
A common way of expressing such a description is through diagrams. By drawing frag-
mentsofgraphsthatrepresentcommonpatternsinyourdata,youcanvisualizeyourmodel
in an intuitive way. In the early stages of Neo4j data modeling, a pen and a whiteboard, a
sheet of paper, or a napkin is often all you need to start discussing what your data will look
like.
2.1.1. Modeling with diagrams: a simple example
Suppose that instead of friendships between individuals, you were interested in modeling
associationsbetweengroupsofpeople.Agroupmightcontainseveralpeople,andaperson
might belong to several groups. In a traditional RDBMS, you'd typically model this scen-
ario using three tables: a table for people, a table for groups, and a join table that would be
used to link people to groups in a many-to-many relationship ( figure 2.1 ) .
Figure 2.1. Users and groups in an RDBMS with a join table