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Add a Hierarchical Recursive Relationship

You can add a hierarchical recursive (single-table recursion) relationship in a logical model when a parent entity or table can have any number of children, but a child can only have one parent. Perform the following steps to add a hierarchical 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 Non-identifying Relationship icon on the erwin Toolbox.
  4. Click the parent entity or table, pause briefly, then click the entity or table again.
  5. Double-click the relationship line to open the Relationships editor.
  6. Click the General tab, and enter a verb phrase to explain the recursive relationship.
  7. 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.