Relationships and Domains › Relationships in the Logical Model › Add a Network Recursive Relationship

Add a Network Recursive Relationship

You can add a network recursive (double-table recursion) relationship in a logical model when a parent entity or table can have any number of children, and a child can have any number of parents. Perform the following steps to add a network recursive relationship:

1. Click the Entity icon on the erwin Toolbox, then click anywhere on the diagram window.
2. Name the parent entity or table and add the primary and non-key attributes or columns.
3. Click the Entity icon on the erwin Toobox, then click anywhere on the diagram window.
4. Name the child entity or table.
5. Click Non-identifying Relationship icon on the erwin Toolbox.
6. Click the parent entity or table, then click the child entity or table.
7. Double-click the relationship line to open the Relationships editor.
8. Click the General tab, and enter a verb phrase to explain the recursive relationship.
9. Click the Rolename tab, assign a descriptive rolename to the migrated foreign key attributes or columns based on the relationship, then click OK to close the Relationships editor.
10. Repeat steps 2-9 to create a second recursive relationship.