Re: Normalizing Tree Data

From: cr113 <cr113_at_hotmail.com>
Date: Mon, 11 Feb 2008 12:40:05 -0800 (PST)
Message-ID: <6fffee7c-5fa2-44cb-984b-0c857afcf316_at_s8g2000prg.googlegroups.com>


On Feb 8, 5:07 pm, Bob Badour <bbad..._at_pei.sympatico.ca> wrote:

> Is the first level always Company? Is the next level always Division? Is
> the next level always Manager? Is the next level always Employee?

Yes.

>
> What does the ID table give you that you don't get from foreign key
> references from Employee to Manager, from Manager to Division, and from
> Division to Company?

IBM
    Div-A

        Jones
        Smith
    Div-B
        Smith

Microsoft

    Div-A

        Johnson
    Div-B

        Jones
        Smith

I'm not sure what you mean by foreign key references.

Do you mean this?

Company Table
Company
IBM
Microsoft

Division Table
Company Division

IBM           Div-A
IBM           Div-B

Microsoft Div-A

Microsoft Div-B

Manager Table
Company Division Manager

IBM            Div-A        Jones
IBM            Div-A        Smith
IBM            Div-B        Smith
Microsoft    Div-A        Johnson
Microsoft    Div-B        Jones
Microsoft    Div-B        Smith

Or this?

Company Table
CompanyKey Company

1                   IBM
2                   Microsoft

Division Table
DivisionKey Division CompanyKey

1                  Div-A       1
2                  Div-B       1
3                  Div-A       2
4                  Div-B       2

Manager Table
ManagerKey    Manager      DivisionKey
1                     Jones          1
2                     Smith           1
3                     Smith           2
4                     Johnson       3
5                     Jones          4
6                     Smith           4

I've tried both of these and they seem to get awkward with 3 or more levels. Are you talking about one of these methods?

> You did not include an Employee table. Is there a difference between the
> Employee table and the Manger table? What is the difference?

I'm just using that as an example. My actual project has 4 levels so I added a 4th level to make it similar. Received on Mon Feb 11 2008 - 21:40:05 CET

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