Briefly explain first, second, and third normal forms. What ...

[sjones]

Briefly explain first, second, and third normal forms.
 
  What will be an ideal response?

Question 2

Describe and give an example of constraints.
 
  What will be an ideal response?

[wergv]

Answer to Question 1

A table is in the first normal form (1NF) if it contains no repeating groups. It is in the second normal form (2NF) if it is in the first normal form and every non-key attribute is fully dependent on the entire primary key. Finally, a table is in the third normal form (3NF) if it is in the second normal form and no non-key attribute is dependent on another non-key attribute.

Answer to Question 2

Constraints are rules that apply to associations: generalization, a patient can be issued many hospital cards but only one card can be valid at any given time.