Mapping rules mapping regular entities relations

CIS3050 Mid-term Review Chapter 1 Introduction to Databases
Components of database environment Fig 1-5

Chapter 2 Data Modeling: ERD for conceptual design

1. Entity type, relationship type,

1. Generalization (bottom up), specialization (top down)

2. Super type and subtype

a. Entity integrity: one PK per table and PK cannot be null

b. Referential integrity: FK refers to PK

2) Multivalued Attribute: Create a separate relation with a foreign key taken from the

original superior entity. Or flatten the multi-valued attribute into the original table.

key comes from the PK in the parent table. FK and PK must have the same domain.

5) Mapping M:N relationship: Create a new intersection table. The composite primary key

8) Mapping Supertype and subtype to tables. One table for a supertype and one table for

each subtype. Relationship between supertype and subtype is One: One. Referential

 Identify partial dependencies, transitive dependencies and full dependencies by performing

functional dependency analysis

 Don’t lose any attributes in the original relation