Modeling on Stefan Litsche

Kinship and Reference Types

Fri, 04 Nov 2022 10:20:00 +0100

Kinship

In the middle of the 19th century the anthropologist Lewis Morgan investigated the society and relationships among American aborigines. He observed that native Americans used a terminology for their relationships which do not match the family in which they lived. A couple of man and woman was living together for a long period which made it clear what their children were. However a man called “children” all offspring of him and of his brothers. All offspring of his sisters were his nephews and nieces. The same was true for woman. A mother called all her offspring and the offspring of her sisters “children”.

Unique is not enough

Wed, 22 Dec 2021 10:20:00 +0100

On our way from monolithic applications to a microservice architecture a property provided by databases got lost — the unique constraint. We need an approach to mitigate the consequences of this missing property.

Why an `id` is not sufficient

When designing a database schema it is considered a good habit to use a natural key as primary key. If our database table contains information about things which we can point at (e.g. items in a warehouse, houses in a street), we often are able to use a natural key . Those things are labeled with a name and we can use that name as a natural primary key in our table. In this case uniqueness ensures identity of our table with the real world.

Adressen im ERP

Wed, 27 Jan 2010 15:14:00 +0100

Das Thema Adressen versus Personen ist immer wieder spannend. Und Quelle von Verwirrungen.

ERP Systeme verwalten in der Regel Adressen als komplexe Attribute von Aufträgen. Für das Abwickeln von Aufträgen ist das ausreichend. Diese werden jedoch zunehmend mit CRM Funktionen angereichert. Vom Standpunkt des Marketings ist die Adresse nicht allein eine Adresse, sondern sie identifiziert eine Person. Über die möchte das Marketing jedoch möglichst viel wissen. Aus diesem Ansatz entsteht der Wunsch, Dubletten zu vermeiden. Aber in der Wirklichkeit hat ein Mensch nicht nur eine Adresse. Darum braucht es ein Konstrukt in der Software, dass Adressen zusammenfasst, die Person.

Modeling on Stefan Litsche

Kinship and Reference Types

Kinship

Unique is not enough

Why an id is not sufficient

Adressen im ERP

Why an `id` is not sufficient