Which are the keys within my table?

Hi everyone, I’m attempting to setup a database for my little snooker club and was wondering if anyone could help me determine which attributes are the keys for this relationship? I really want to make sure all the keys are right before I start normalisation...



Note: coachId and coachName are membership no and last name of the coaching player whereas PlayerId, PlayerName, and playerRanking are the number, last name and ranking position of the person being coached.



Table:



Coaches(coachId, CoachName, PlayerID, PlayerName, PlayerRanking, StartDate, EndDate, TourID, TourName)



Heres full dependences Ive come up with…



{PlayerId, StartDate, EndDate} > coached

PlayerId > {PlayerName, PlayerRanking }

{PlayerId, TourId } > coachId

{PlayerId, TourId } > coachName

{PlayerId, StartDate, EndDate} > coachName

TourID > TourName

CoachId > CoachName

{ PlayerId, TournID } > StartDate

{ PlayerId TourID }> EndDate



Any help is much appretiated



Cheers Guys,

GolfingTea.

Hey GolfingTea!

For what I understood...You would have:

Coaches
CoachID
CoachName

Players
PlayerID
PlayerName
PlayerRanking
CoachID

Tours
TourID
StartDate
EndDate

ToursPlayers
TourID
PlayerID

Attributes in blue are the Pkey of the table
Attributes in gray are simple fields of the table
Attributes in red are Fkeys

I didn't understand much your dependencies...so Here're the ones I came up with (a --> b means you can determin the value of b, knowing a):

CoachID --> CoachName (and other coach personal data)
PlayerID --> PlayerName, PlayerRanking (and other player personal data)
TourID --> StartDate, EndDate (this attributes are independen from the player)

Since you can have many Players going to many tours, you may have a ToursPlayers table to know what players went to what tours. The Primary key is formed by both attributes!

Good Luck!

Anibal.