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Data Modeling › Data Model › Select Each Entity’s Unique Identifier

Select Each Entity’s Unique Identifier

Each entity must be uniquely identifiable so that each instance of the entity is separate and distinctly recognizable from all other instances of that entity. The unique identifier, also known as the primary key, can be any of the following:

A primary key should consist of the fewest number of attributes necessary to make every instance of the entity unique. Review the attributes of each entity and select the primary key for each entity. Primary keys are identified in the following table:

Entity

Attribute

Primary Key

COURSE

Course code
Course name

Course code

HORSE

Horse code
Horse name
Horse gender
Date of birth

Horse code

JOCKEY

Jockey code
Jockey name
Jockey gender

Jockey code

SIRE

Sire code
Sire name
Sire Date of birth

Sire code

DAM

Dam code
Dam name
Dam Date of birth

Dam code

RACE

Course code
Course name
Race date
Race time
Race name
Going conditions
Distance
Prize money
Horse code
Horse name
Horse gender
Date of birth
Jockey code
Jockey name
Finishing position
Handicap
Entry status

Course code
Race date
Race time