Defining the data model
Defining the data model means defining object types ( Structures ), classifications ( Enumerations ) and collections ( Extents ), In contrast to relational databases, where the table definition is a structure and a collection definition, the terminology database provides different definitions for structures and collections. Thus, several collections might be defined for the same structure.
In order to benefit most from default settings provided by the class editor, we suggest the following steps:
- Define structures relevant for your application (so far you know, which structures are required).
- Define attributes, enumerations and keys for each structure (but not yet relationships).
- Define extents for those structures, that need to store data with a global entry point (e.g. addresses, which might be a property of persons, only, do not require an extent).
- Define references (parts) and relationships for the structures.
When you keep this order, you will get a lot of benefits, when defining the relationships and references, since the system has got already sufficient information in order to support you as much as possible. When you not keep this sequence, this is not a problem, since one may enter all the required information later on and the check feature shows you anyhow, where something is wrong.
After you did initialize the project, you get an empty database with your project in the left side tree. After you expanded the project and select Structures , one may start defining your object types It takes a few seconds, until the structure definition window appears, since the form has to be loaded when being accessed the first time.
