As we saw in the list of relationships at the end of last week’s newsletter, most relations do not demand one and only one connected object. It is much more common for the limit of one object to be only on one end of the connection. […]
Optional one-to-one relationships Optional one-to-one relationship are more common than mandatory one-to-one relationships, both in life and in data modelling. Sometimes an object may be optionally connected to at least one other object. One example is a car, which may be registered or licensed for use on the road or it may be allowed to [...]
Types of connections Connections are the most important and difficult things in modelling. Objects only rarely exist with no connections to other objects. The saying “No man is an island”[1] expresses this with regard to people, and other objects are just the same. […]
In this article we continue our simple data modelling example. We have named our database table, and now we need columns to store the information about each pot. Naming columns is another minefield, just like naming tables. All sorts of logic can be applied to avoid naming conflicts and ensure consistency. We will ignore this [...]