ER to Relational Model 157A (4) NO FLASH CARDS!! BETTER TO LOOK AT SLIDES

Question 1

ER to Relational Model

Step 1: Regular Entity Types

Answer 1

● For each regular/strong entity type, create a corresponding relation that includes all the simple attributes (includes simple attributes of composite relations)
● Choose one of the key attributes as primary.
○ If composite, the simple attributes together form the primary key
● Any remaining key attributes are kept as secondary unique keys (these will be useful for physical tuning w.r.t. indexing analysis)

Question 2

ER to Relational Model

Step 2: Weak Entity Types

Answer 2

● For each weak entity type, create a corresponding relation that
includes all the simple attributes.
● Add as a foreign key all of the primary key attribute(s) in the entity
corresponding to the owner entity type.
● The primary key is the combination of all the primary key attributes
from the owner and the partial key of the weak entity, if any.

Question 3

Step 3: Mapping Binary 1-to-1