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Data Flow Diagram: Assignment

Added on - 13 Sep 2021

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1.Data Flow Diagram
2.Attributes and relationships
rider
oriderID
oname
oage
ophoneNumber
Team
oteamID
oname
ocategory
olapCount
ototalTime
ocategoryPosition
ooverallPosition
race
olapDistance
ostartTime
laps
olapID
otime
ospeed
3.Entity relationship diagram
4.Candidate keys- The candidate keys are shown in bold.
Team (teamID, name, category, lapCount, totalTIme, categoryPosition, overallPosition)
Candidate key (teamID)
Rider (riderID, name, age, phoneNumber)
Candidate key (riderID)
Race (lapDistance, startTime)
Candidate key (lapDistance, startTime)
lap (lapID, time, speed)
Candidate key (lapID, time, speed)
5.Primary keys
Team (teamID, name, category, lapCount, totalTIme, categoryPosition, overallPosition)
Primary key(teamID) – This is the best attribute to be the primary key because every team has a
unique teamID.
Rider (riderID, name, age, phoneNumber)
Primary key(riderID)- This is the best attribute for the primary key because every rider has a
unique riderID.
Race (raceID, lapDistance, startTime)
Primary key(raceID)- Every race has should have a unique raceID thus this should qualify to be
the primary key.
lap (lapID, riderID, time, speed)
Primary key(lapID,riderID)- Every lap has a unique lapID thus this qualifies to be the primary key
6.Primary keys and foreign keys
Race (raceID, lapDistance, startTime)
Primary key(raceID)- Every race has should have a unique raceID thus this should qualify to be
the primary key.
Team (teamID, name, category, lapCount, totalTIme, categoryPosition, overallPosition,raceID)
Primary key(teamID) – This is the best attribute to be the primary key because every team has a
unique teamID.
Foreign key(raceID) references race (raceID)
Rider (riderID, name, age, phoneNumber,teamID)
Primary key(riderID)- This is the best attribute for the primary key because every rider has a
unique riderID.
Foreign key(teamID) references team (teamID)
lap (lapID, riderID, time, speed)
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