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Translating from ER to Relationship Schema

Translating from ER to Relationship Schema. Adapted from Juliana Freire. The easy part. Entity  relation with attributes underlined field is key Relationship -> relation? special situations – Multi-valued and composite attributes – Weak entity sets – ISA relationships

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Translating from ER to Relationship Schema

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  1. Translating from ER to Relationship Schema Adapted from Juliana Freire

  2. The easy part Entity  relation with attributes underlined field is key Relationship -> relation? special situations – Multi-valued and composite attributes – Weak entity sets – ISA relationships – Relations that result from an entity set and 1tomany relationship

  3. Translating Many-to-Many

  4. One to Many

  5. One to Many answer

  6. One – to- Many

  7. One to Many with total participation

  8. Why not a new relation?

  9. Mapping many to many attribute

  10. Throw the attributes onto the relationship table

  11. 1-to-many relationship with an attribute?

  12. Add it to the 1 side

  13. Translating Weak Entity Sets

  14. Translating ISA relationship – as a tier

  15. Translating ISA – one with all

  16. Which one?

  17. Participation Constraints

  18. Splitting tables is always an option

  19. Sample ERD

  20. Equivalent Relational Schema

  21. Translate This

  22. Translation steps

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