1. 	 Identify all of the correct statements that complete this sentence: A primary key is: (Choose Three)	 Mark for Review 
(1) Points
					
			(Choose all correct answers)	
					
			
	A single column that uniquely identifies each row in a table (*)

			
	A set of columns that uniquely identifies each row in a table (*)

			
	A set of columns and keys in a single table that uniquely identifies each row in a single table (*)

			
	Only one column that cannot be null

					
				
Incorrect		Incorrect. Refer to Section 11 Lesson 1.

					
		2. 	 A table does not have to have a primary key. True or False?	 Mark for Review 
(1) Points
					
			
	True (*)

			
	False

					
				
Incorrect		Incorrect. Refer to Section 11 Lesson 1.

					
		3. 	 One or more columns in a primary key can be null. True or False?	 Mark for Review 
(1) Points
					
			
	True

			
	False (*)

					
				
Correct		Correct

					
		4. 	 A foreign key always refers to a primary key in the same table. True or False?	 Mark for Review 
(1) Points
					
			
	True

			
	False (*)

					
				
Correct		Correct

					
		5. 	 Foreign keys cannot be null when	 Mark for Review 
(1) Points
					
			
	It is part of a primary key (*)

			
	It refers to another table

			
	It contains three or more columns

					
				
Incorrect		Incorrect. Refer to Section 11 Lesson 1.

					
		6. 	 Column integrity refers to	 Mark for Review 
(1) Points
					
			
	Columns always having values

			
	Columns always containing positive numbers

			
	Columns always containing values consistent with the defined data format (*)

			
	Columns always containing text data less than 255 characters

					
				
Incorrect		Incorrect. Refer to Section 11 Lesson 1.

					
		7. 	 The explanation below is an example of which constraint type? 
A primary key must be unique, and no part of the primary key can be null.	 Mark for Review 
(1) Points
					
			
	Entity integrity (*)

			
	Referential integrity

			
	Column integrity

			
	User-defined integrity

					
				
Correct		Correct

					
		8. 	 The explanation below is an example of which constraint type? 
A column must contain only values consistent with the defined data format of the column	 Mark for Review 
(1) Points
					
			
	Entity integrity

			
	Referential integrity

			
	Column integrity (*)

			
	User-defined integrity

					
				
Incorrect		Incorrect. Refer to Section 11 Lesson 1.

					
		9. 	 The explanation below is an example of which constraint type? 
The value in the dept_no column of the EMPLOYEES table must match a value in the dept_no column in the DEPARTMENTS table.	 Mark for Review 
(1) Points
					
			
	Entity integrity

			
	Referential integrity (*)

			
	Column integrity

			
	User-defined integrity

					
				
Correct		Correct

					
		10. 	 The explanation below is an example of which constraint type? 
If the value in the balance column of the ACCOUNTS table is below 100, we must send a letter to the account owner which will require extra programming to enforce.	 Mark for Review 
(1) Points
					
			
	Entity integrity

			
	Referential integrity

			
	Column integrity

			
	User-defined integrity (*)

					
				
Incorrect		Incorrect. Refer to Section 11 Lesson 1.