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  #1 (permalink)  
Old 11-15-10, 09:54
jeffries jeffries is offline
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Normalisation

Hi
Just starting lectures in normalisation so this will seem a bit simple to some of you

have a relation in 1NF

carReg make model custNo custName hireDate

R111EEE ford escort c100 smith J 14/05/01
R111EEE ford escort c201 owen P 15/05/01
T666TTT nissan sunny c100 smith J 20/06/01
Y666YYY ford mondeo c413 blatt S 14/05/01
Y666YYY ford mondeo c200 smith J 20/05/01
H888HHH nissan sunny c295 owen P 20/05/01
Y666YYY ford mondeo c413 blatt S 10/06/01
R111EEE ford escort c100 smith J 12/07/01

Assuming a customer can hire only one car on the same date but may hire the same car on different dates and that the functional dependencies represented by the data in the relation will hold for any additional data identify the functional dependencies represented by the data in the relation.

I have the following

(carReg, hireDate).......(make,model,custNo,custName) primary key
(carReg,custNo)........(make,model,custName) candidate key
(carReg)........(make,model) partial dependency
(custNo,hireDate).........(carReg,make,model,custN o) candidate key
(custNo).......(custame) transitive dependency

Can someone let me know if I am on the right tracks

Thanks
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Old 11-15-10, 09:59
pootle flump pootle flump is offline
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Along the right tracks but wrong.

To start not all your keys are right.

To what normal form are you expected to normalise?
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Last edited by pootle flump; 11-15-10 at 10:05.
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Old 11-15-10, 10:39
jeffries jeffries is offline
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That is the full question

ll I have to do is identify the functional dependencies
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Old 11-15-10, 10:56
pootle flump pootle flump is offline
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You can't do that without getting your keys right.
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Old 11-15-10, 11:08
jeffries jeffries is offline
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what keys have i got wrong

What should be the candidate keys and primary keys

Thanks
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Old 11-15-10, 11:16
pootle flump pootle flump is offline
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I'm not telling you; telling you this much is a massive help for you.

Look at your keys again, and refer each of them back to the text. One or more of them are supported by the text. One or more of them is not supported by the text. The same is true of the data as well if you refer your keys back to that.
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Old 11-15-10, 11:23
jeffries jeffries is offline
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Thanks for your help
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