1.6) Constraints should be used to force valid data entry / modification to the database True O False O False O False O 1.7) A primary key can contain only single row with null value since duplicate...

1.6) Constraints should be used to force valid data entry / modification to the database
True 
False 
1.7) A primary key can contain only single row with null value since duplicate values are not allowed
True 
False 
1.8) Comparison with null can be meaningfully done with equals and not equals operator
True 
False 

Extracted text: 1.6) Constraints should be used to force valid data entry / modification to the database True O False O False O False O 1.7) A primary key can contain only single row with null value since duplicate values are not allowed True O 1.8) Comparison with null can be meaningfully done with equals and not equals operator True O