Logical Model - Part I
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It is clear that
entities:
- Point System
- Tournament
- Tournament Round
- Player
can be modelled the same
way they are in the business model. In other words, the above
entities map to a relvar each with the same attributes as in the
business model. The relvar specifications are presented in the
following format:
Relvar
Name
Heading:
{Set of attributes}
Key:
{Set of Attributes}, …
Predicate:
A statement that describes the intented meaning of the relvar.
{}
- denotes a set
Assume that the data
type NAME is available in the RDBMS of choice.
Another assumption is that tournament name
can change and, because of that, it’s not suitable for a key.
The specifications of
the mentioned relvars follows.
POINTSYSTEM
Heading:
{POINTSYSTEMNAME(STRING)}
Key:
{POINTSYSTEMNAME}
Predicate:
Point system named §pointsystemname§ can be used for ranking.
TOURNAMENT
Heading:
{TOURNAMENTID(INT) TOURNAMENTNAME(NAME) TOURNAMENTSTARTDATE(DATE)
TOURNAMENTENDDATE(DATE) POINTSSYTEMNAME(STRING)}
Key:
{TOURNAMENTID} {TOURNAMENTNAME}
Predicate:
Tournament idendified by §tournamentid§ is titled $tournamentname$,
starts/started on §tournamentstartdate§ and ends/ended on
§tournamentenddate§ and uses point system §pointsystemname§.
TOURNAMENTROUND
Heading:
{TOURNAMENTID(INT) ROUNDID(INT) ROUNDEXPECTEDSTARTDATE(DATE)
ROUNDEXPECTEDENDDATE(DATE)}
Key:
{TOURNAMENTID, ROUNDID}
Predicate:
Round number §roundid§ of tournament §tournamentid§ has expected
start date of §roundexpectedstartdate§ and expected end date of
§roundexpectedenddate§.
PLAYER
Heading:
{PLAYERID(INT) PLAYERNAME(NAME)}
Key:
{PLAYERID} {PLAYERNAME}
Predicate:
Player idendified by §playerid§ is named §playername§.
Obviously, the complex
part is designing logical model for Match Draw and Match Score. It's presented in Part II of the Logical Model.
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