What is 1NF and 3NF when referring to Keys ?

What is 1NF and 3NF when referring to Keys ?

Post by Edward M » Thu, 09 Dec 1993 05:38:36



        Does anyone know what is the meaning of 1NF and 3NF when referring to
keys ?

                                                                thanks you

 
 
 

What is 1NF and 3NF when referring to Keys ?

Post by Howie Michals » Fri, 10 Dec 1993 00:26:43


NF == Normal Form so, 1NF means 'First Normal Form', 3NF means 'Third
Normal Form' ...  I'll see if I can dig up a 'whitepaper' style document
that details each form - the last I heard there were 7 accepted levels
of normalcy (with those up to 9 floating around).

Cheers,
Howie



>    Does anyone know what is the meaning of 1NF and 3NF when referring to
>keys ?

>                                                            thanks you

--


Sybase, Inc.                               Voice/Work:  301.897.1704
         [Opinions are my own and NOT those of my employer]

 
 
 

1. 1NF to 3NF

ORIGINAL STARTING FORM

AC_NUM = aircraft number
MODEL = model of the plane
MANUF = manufacturer of plane
TYPE = type of plane (single engine etc..)
AC_CHARGE = aircraft charge per hour
DATE = date flown
TYPE = type of instruction
HOURS= hours flown
INSTR = flight instructor
I_Charge = instructor charge
TTAF = total time on air frame
TTEL = total time on left engine
TTER = total time on right engine
CUST = customer number

given this information I neet to convert from first normal form to third
normal form. I am having trouble understanding partial and transitive
dependancies. How do I break this down when the composite primary key is
CUST, HRS, DATE and AC_NUM?

2. Convert from APT?

3. Foreign Keys and 3NF

4. OCI

5. Modifying a table that other tables refer to for foreigh key

6. Displaying Oracle's BLOB or Sybase's binary objects as hex digits

7. Select for update in a session does not ban insert referring key in another

8. HELP! Whats wrong with this code?VC1.52

9. AM (Char 253) in key. D3/NT

10. @AM and other bad characters in key in Universe

11. 1NF vs Seth

12. data normalisation UNF to 1NF