| | |
Doubt about 2NF
Please support our Database Design advertiser: PostgreSQL or MySQL? Compare and contrast the two most popular open source databases
![]() |
Hi,
I was reading the book "Fundamentals of Database Systems" by Elmasri and Navathe. In that it is given that for a relation to be in 2nd NF, every non prime attribute (attribute which is not a part of any candidate key) should be fully functionally dependent on any candidate key.
Also a relation is given as
EMP_DEPT(ENAME,SSN,BDATE,ADDRESS,DNUMBER,DNAME)
where,
EMP_DEPT- Employee Department
ENAME- Employee Name
SSN-Social Security Number
BDATE-Birthdate
DNUMBER- Dept Number
DNAME- Dept Name
This is said to be in 2NF.
However if you see the DNAME attribute which is non prime (not a part of candidate key), it is not functionally dependent on any candidate key (SSN in this case).
So is it correct that the relation is in 2NF or is there something that I have missed?
Thanks
I was reading the book "Fundamentals of Database Systems" by Elmasri and Navathe. In that it is given that for a relation to be in 2nd NF, every non prime attribute (attribute which is not a part of any candidate key) should be fully functionally dependent on any candidate key.
Also a relation is given as
EMP_DEPT(ENAME,SSN,BDATE,ADDRESS,DNUMBER,DNAME)
where,
EMP_DEPT- Employee Department
ENAME- Employee Name
SSN-Social Security Number
BDATE-Birthdate
DNUMBER- Dept Number
DNAME- Dept Name
This is said to be in 2NF.
However if you see the DNAME attribute which is non prime (not a part of candidate key), it is not functionally dependent on any candidate key (SSN in this case).
So is it correct that the relation is in 2NF or is there something that I have missed?
Thanks
My blog on .NET- http://dotnet.tekyt.info
![]() |
Similar Threads
- java doubt - urgent (Java)
- doubt about header file implementation (C++)
- clarify my doubt (Java)
- doubt abt uploading the database (MySQL)
- i am a to c programing..and a doubt about pointers (C)
- can anyone clear my doubt? (Computer Science)
- Doubt about compiling. (Legacy and Other Languages)
Other Threads in the Database Design Forum
- Previous Thread: Car Hire Firm Database
- Next Thread: Need Help on Informatica
| Thread Tools | Search this Thread |





