中等ICT-DBAS-005
Why is a student name a weak primary key?
A. Two students can have the same name, so the key would not be unique.✓ 答案
B. A name cannot be displayed on a form.
C. Names are always numbers.
D. A name is a WAN.
解說
A primary key must be unique. Shared names break that rule. A student number issued once does not.