Introduction to modeling nodes and relationships

We looked at the data models in Figure 2.2. Without delving into technical details, we can say that "A person can fly from New York to London on carrier X". With this statement, we can start exploring possibilities in which this data can be modelled. A preliminary approach would be to mark cities as nodes and flights as relationships, as shown in the following figure:

Figure 2.3: A preliminary model with flights and cities—the property graph

This might seem to be a fair model, however, there are a few problems with the approach. Relationships, in graphs, are used to model how the entities' nodes are related to each other. As discussed earlier, flights are one of the two core entities in our model. Flights don't relate cities to each other, instead, they are a means to get from one city to another. Modeling flights as relationships, can work out in presenting a flight plan, but if we have to allow flight bookings in the future, then we need to...