ER/Studio - Embarcadero Technologies Product Documentation

USING ER/STUDIO > DEVELOPING THE LOGICAL MODEL
Creating and Editing Relationships
Creating and Editing Recursive Relationships
A recursive relationship associates an object with itself; the object is both the parent and child. For example, you can
have an employee who manages many employees and each employee is managed by one employee. The employee
entity has a recursive relationship to itself.
If you have a recursive relationship, you must assign rolenames to the relationship. Use the Recursive Relationship
dialog to specify rolenames for a foreign key that is inherited more than once within the same entity. For example, if a
recursive relationship is created where one entity is designated as both the parent and child entity, then the primary
key is propagated within the entity. ER/Studio automatically opens the Recursive Relationship dialog box when it
detects overlapping foreign keys in an entity.
The steps for adding recursive relationships are slightly different from adding regular relationships; however, you can
for edit and delete recursive relationships in the same manner as for regular relationships.
1 Click Insert > Insert Relationship, and then select a non-identifying relationship type.
2 On the Data Model Window, click the object to which you want to apply the recursive relationship, and then click
it again.
3 Complete the Recursive Relationship or Recursive Relationship for Multiple Keys dialog box, and then click
OK.
4 Right click anywhere on the Data Model to revert to the Selection tool.
Notes
• If you have a recursive relationship, the Recursive Relationship editor appears where you must assign a
rolename to the primary key or to at least one attribute of the primary key. The rolename cannot be the same as
the attribute or column name. In order for the foreign key to appear in the child, it must be assigned a rolename
so it can be differentiated it from the native key.
• If you have a recursive relationship where multiple foreign keys that are inherited more than once within the same
entity, the Recursive Relationship for Multiple Keys dialog display where you specify rolenames for each foreign
keys. For example, if a recursive relationship is created, where one entity is designated as both the parent and
child entity, then the primary keys are propagated within the entity.
• Edit the rolenames associated with the relationship by right-clicking the relationship in the Data Model Window,
and then selecting Edit Rolenames.
• Navigate between the parent and child object by right-clicking the object and then selecting Navigate to Parent or
Navigate to Child from the shortcut menu.
Creating View Relationships
The steps to adding and deleting view relationships are the same as those of regular relationships. However, view
relationships are a special type of relationship used to propagate attributes from an entity or a view to a view. When
adding a view relationship, the end point of the relationship must be a view. View relationships cannot be edited, but
they can be deleted. To determine which attributes of an entity can be propagated from the parent entity or view to the
child view, use the View Editor - Column Tab.
NOTE: In order for view relationships to display, you must enable the options to display views and view
relationships on the View tab of the Diagram and Object Display Options dialog. Click View >
Diagram and Object Display Options.
EMBARCADERO TECHNOLOGIES > ER/STUDIO® 8.0.3 USER GUIDE 136