Composite Primary Key

Question

0.00/5 (No votes)

See more:

I am using an Oracle database. The schema has four tables:

Table 1: worker (name , id , sex , salary , specialty )
Table 2: customer (name , id , bill , date of visit)
Table 3: service (servise id , type)
Table 4: order (orderNo , worker id , worker name , serviceID , date , custemorID)

I think orderNO is the PK and workerNAME and workerID are the composite PKs. Both are FKs. :confused:

My question: In table 4, which one of the attributes is the composite PK?

Posted 30-Dec-10 4:29am

malemar

Updated 30-Dec-10 5:08am

Slacker007

v2

Add a Solution

Comments

Slacker007 30-Dec-10 11:09am

Reformatted and corrected spelling and grammar.

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Hiren solanki · Answer 1 · 2010-12-30T06:05:00

I seems your question little bit generic.

you asked Which one of the attributes is the composite PK ? Rather it should be Which one of the attributes should be the composite PK.

Now lets move on to your answer.

In Table 4 you already kept OrderNo as primary key and I think it's correct PK. Now why you want to make another composite PK ?

Composite PK is only use when one key is not enough to be a primary key.

If OrderNo is PK then I don't think of another Composite PK.

Further clarification on the question can give us little more understanding about.

malemar · Answer 2 · 2010-12-30T08:04:00

Solution 2

ok
one question more

so there is no composite PK in any table.

now in ER digram I put under attribute (OrderNo) Fragmented line like -----

what is the meaning of this line (------)? >> in ERD

and If I make the OrderNo PK, is it affects when I create the tables in the oracle ??

Posted 30-Dec-10 8:04am