Consider a relational table with a single record for each registered student with the following attributes.
1. Registration Num: Unique registration of each registered student.
2. UID Unique identity number, unique at the national level for each citizen.
3. Name: Name of the student.
4. BanIcAccount Num: Unique account number at the bank. A student can have multiple account or joint accounts. This attribute stores the primary account number.
5. Hostel_Room: Room number ofhe hostel.
Which ofthe following option is INCORRECT?
| A. | BankAccount Num is a candidate key. |
| B. | Registration Num can be a primary key |
| C. | UID is candidate key if all students are from same country. |
| D. | If S is a superkey such that S ∩ UID is NULL then S ∪ UID is also a superkey. |
Answer : A Explanation : |
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Option: A Explanation : Explanation will come here. Explanation will come here. Explanation will come here. Explanation will come here. Explanation will come here. |
