Key columns and primary keys - Quiz

RelationalDBDesign

Key columns and primary keys - Quiz

Each question is worth one point. Select the best answer for each question.

1.	A concatenated primary key is made up of what? Please select the best answer.
	A.	A single column that occurs in many relations
	B.	Multiple columns that occur in many relations
	C.	Multiple columns from a single relation
	D.	A single column from a single relation

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.

3.	When creating a primary-key column, you should use fields containing what type of values? Please select all the correct answers.
	A.	Unique values for every record
	B.	Values that are unlikely to change
	C.	Values that are not null
	D.	Values that contain meaningful information