中等ICT-DBAS-002
A primary key must:
A. Uniquely identify each record and must not be left empty.✓ 答案
B. Be allowed to repeat whenever two people share a name.
C. Always be a person's name.
D. Be a kind of malware.
解說
Uniqueness and no empty value are the rules. A name fails when two students share it, so a school-issued number is safer.