Results 1 to 7 of 7
  1. #1
    Uranium Lounger CWBillow's Avatar
    Join Date
    Jul 2002
    Location
    Las Vegas, NV USA
    Posts
    6,371
    Thanks
    78
    Thanked 12 Times in 11 Posts

    Achieving 1NF (2007)

    I'm not getting this idea at all.

    I get that 1NF requires no repeating (potentially) fields, and has a primary key, yes?

    Okay. So if the present form is

    CLIENT
    (ClientNumber, ClientName, VetID, VetName,
    (PetID, PetName, PetType))

    and according to the terminology as I get it, the fields in the "double-parens" are repeating. So do I make two tables, using the PetID as the PK, so that the PetName would not repeat...but how? Use the PetID as a PK to link the two, as

    (PetID, PetName, PetType, ClientNumber, ClientName) and (PetID, VetName, VetID)

    Would that then be in 1NF? 'Cause then each record would be unique to each table, and yet the tables are linked via the PK?

    Regards,
    Chuck Billow
    -------------------------------------------------
    "Good judgment comes from experience, and experience - well, that comes from poor judgment."

    ~ A(lan) A(lexander) Milne (1882-1956)- "House at Pooh Corner"

  2. #2
    Plutonium Lounger
    Join Date
    Mar 2002
    Posts
    84,353
    Thanks
    0
    Thanked 29 Times in 29 Posts

    Re: Achieving 1NF (2007)

    We obviously don't know what the data in this table look like, so it's hard to say how the table should be split.

  3. #3
    Uranium Lounger CWBillow's Avatar
    Join Date
    Jul 2002
    Location
    Las Vegas, NV USA
    Posts
    6,371
    Thanks
    78
    Thanked 12 Times in 11 Posts

    Re: Achieving 1NF (2007)

    Well then, now I *am* stumped Hans.

    "cause all I got for the exercise was

    Consider the following relation:

    CLIENT
    (ClientNumber, ClientName, VetID, VetName,
    (PetID, PetName, PetType))


    a) What is the repeating group in the relation?

    Convert the un-normalized relation to First Normal Form.

    Regards,
    Chuck
    -------------------------------------------------
    "Good judgment comes from experience, and experience - well, that comes from poor judgment."

    ~ A(lan) A(lexander) Milne (1882-1956)- "House at Pooh Corner"

  4. #4
    Plutonium Lounger
    Join Date
    Mar 2002
    Posts
    84,353
    Thanks
    0
    Thanked 29 Times in 29 Posts

    Re: Achieving 1NF (2007)

    Don't they provide any description in words of what the data mean?

  5. #5
    Uranium Lounger CWBillow's Avatar
    Join Date
    Jul 2002
    Location
    Las Vegas, NV USA
    Posts
    6,371
    Thanks
    78
    Thanked 12 Times in 11 Posts

    Re: Achieving 1NF (2007)

    Nothing. That was it.

    Chuck
    -------------------------------------------------
    "Good judgment comes from experience, and experience - well, that comes from poor judgment."

    ~ A(lan) A(lexander) Milne (1882-1956)- "House at Pooh Corner"

  6. #6
    Plutonium Lounger
    Join Date
    Mar 2002
    Posts
    84,353
    Thanks
    0
    Thanked 29 Times in 29 Posts

    Re: Achieving 1NF (2007)

    I would say that the client and vet data are being repeated - if a client has 37 pets, the name of the client would be repeated 37 times. So you need a primary key for the client/vet data, and split of the pet data into a child table that links to the client table

    CLIENT
    (ClientID (PK), ClientNumber, ClientName, VetID, VetName)

    PET
    (PetID (PK), PetName, PetType, ClientID (FK))

    where PK = primary key, FK = foreign key.

    I assume that you will have to split the client table again, but that's probably the next step.

  7. #7
    Uranium Lounger CWBillow's Avatar
    Join Date
    Jul 2002
    Location
    Las Vegas, NV USA
    Posts
    6,371
    Thanks
    78
    Thanked 12 Times in 11 Posts

    Re: Achieving 1NF (2007)

    Good grief!

    I *think* I see what you've done. I'll try it and see.

    Thanks, Hans.

    Regards,
    Chuck
    -------------------------------------------------
    "Good judgment comes from experience, and experience - well, that comes from poor judgment."

    ~ A(lan) A(lexander) Milne (1882-1956)- "House at Pooh Corner"

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •