« previous next »

Author Question: Briefly explain first, second, and third normal forms. What will be an ideal ... (Read 96 times)

sjones

  • Hero Member
  • *****
  • Posts: 520
on: Jul 7, 2018
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

  • Sr. Member
  • ****
  • Posts: 365
Reply #1 on: Jul 7, 2018
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.


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
« previous next »
 

Did you know?

The top five reasons that children stay home from school are as follows: colds, stomach flu (gastroenteritis), ear infection (otitis media), pink eye (conjunctivitis), and sore throat.

Did you know?

Egg cells are about the size of a grain of sand. They are formed inside of a female's ovaries before she is even born.

Did you know?

In ancient Rome, many of the richer people in the population had lead-induced gout. The reason for this is unclear. Lead poisoning has also been linked to madness.

Did you know?

Asthma-like symptoms were first recorded about 3,500 years ago in Egypt. The first manuscript specifically written about asthma was in the year 1190, describing a condition characterized by sudden breathlessness. The treatments listed in this manuscript include chicken soup, herbs, and sexual abstinence.

Did you know?

Only one in 10 cancer deaths is caused by the primary tumor. The vast majority of cancer mortality is caused by cells breaking away from the main tumor and metastasizing to other parts of the body, such as the brain, bones, or liver.

A missense mutation that converts the normal ras gene into an oncogene. A missense mutation that converts the normal ras gene into an oncogene.
Hematocrits, left to right: normal, anemia, polycythemia. Hematocrits, left to right: normal, anemia, polycythemia.
Mass Wasting Forms Mass Wasting Forms
Expulsion of fetus and afterbirth during normal delivery. The afterbirth consists of the placenta, t Expulsion of fetus and afterbirth during normal delivery. The afterbirth consists of the placenta, t
Normal physiologic mechanisms of the body that restore homeostasis to the balance of serum calcium Normal physiologic mechanisms of the body that restore homeostasis to the balance of serum calcium
Video: Monohybrid crosses

For a complete list of videos, visit our video library