Relationships and Domains › Relationships in the Physical Model › Optional Non-Identifying Relationships in the Physical Model

Optional Non-Identifying Relationships in the Physical Model

In an optional non-identifying relationship, the columns that are migrated into the non-key area of the child table are not required in the child table. This means that nulls are allowed in the foreign key. An optional non-identifying relationship is drawn differently depending on the notation for your model:

• IDEF1X notation draws a dashed line with a solid dot on the child end and a diamond on the parent end.
• IE notation draws a dashed line with a cross and a circle on the parent end. The child end indicates the cardinality with:
  • Crows feet with a cross and a circle (Zero, One or more)
  • Crows feet with a cross (One or more)
  • A cross and a circle (Zero or one)
  • A dashed line (Exactly n)