2. |
A candidate-key field qualifies as a primary-key column if it meets what three conditions?
Please select all the correct answers.
|
|
A. |
The field cannot have a value of zero.
|
|
B. |
Values in the column cannot change.
|
|
C. |
Every record must have a unique value for the column.
|
|
D. |
The field cannot contain a null value.
|