Relational Schema
A relational schema represents a restricted relational data structure.
Creating a Relational Schema
To create a relational schema:
1. Click the navigation menu then Architecture > Hierarchy View.
2. In the edit area, unfold the Database folder.
3. Right-click the name of the database concerned and click New > Relational Schema.
The new relational schema is created. You can open its properties to modify or complete its characteristics.
Relational Schema Diagram
A relational schema is made up of tables and/or physical views and can be described in two types of diagram:
• the table diagram which is used to display a set of tables and their relationships (FK).
• the structure diagram that is used to break down a relation a schema into sub-domains.
You can connect one or more diagrams to a relational schema according to what you want to describe.
To create a diagram from a relational schema:
Right-click on the relational schema and select New followed by the type of diagram (tables or structure).Adding a component to a relational schema
You can connect objects to a relational schema through components.
A relational schema can include:
• Sub-domains, visible in the structure diagram
• Tables or physical views, to which the type of access (read only, modification, deletion, etc.) is defined and which are visible in the relational schema's table diagram.
To add a component to the relational schema:
1. Open the properties of the relational schema in question.
2. Click the Components page.
The first section allows you to add domains.
The second section allows you to add objects of type table or physical view.
3. Click New to add a component.
Defining the access mode to the referenced object
On components of type table or physical view you can define the access mode to the referenced object (creation, read-only, deletion, etc.).
To define the access mode to the object in the relational schema:
1. Open the properties window of the relational schema.
2. Select the Components page.
3. Select the line of the component in question.
Commands are added, including the CRUD button.
4. Click this button.
5. In the window that appears, select or deselect the check boxes associated with the actions: Create, Read, Update, Delete.