Database definition

Database definition means defining the database schema. ODABA provides different ways of defining a database schema.

The most comfortable way is defining the schema using the ODABA Development Environment (ODE). This provides two tools for defining many different types of resources in a dictionary or resource database.

One may also use the ODL script interface. After preparing an ODL script file this can be imported into the dictionary by calling the ODL utility. Details about the script syntax are described in "Language References". The ODL script language completely supports the data model definition and part of the functional model, but one cannot define resource extensions as forms or web controls.

A third way, which is useful in some cases, are schema definitions from within a program. Since the dictionary is an ordinary ODABA database, one may access a dictionary from within a program in the same way as any other database. Thus, one may simply change the schema from within an application.

An object-oriented database definition should include three parts:

1. The data or object model definition

2. The functional model

3. The state or dynamic model

ODABA supports all three model types in any sort of database, i.e. one may refer to system object types in an application database as well as in a dictionary or resource database.