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Hierarchies
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  • A (Dezign) Data Model is shown below and An Access Database is available on request.

    DESIGN NOTES :-
    The design is very simple. Unfortunately, the SQL to retrieve a hierarchy is not so simple.
    The best approach is to use SQL Views to define the layout that you want to display.
    Joe Celko has a comprehensive discussion in Chapter 26 on 'Trees' in his book 'SQL for Smarties' (5 Stars on Amazon).

    Oracle has provided an extension to SQL called CONNECT BY.
    Microsoft has added a Hierarchy ID to SQL Server 2008 which is definitely worth checking out.

    Here is also a version showing 'dotted line' relationships and partial Hierarchy Strings.

    Dezign Data Model for Hierachies

    • Barry Williams
    16th. November 2002
    Principal Consultant
    Database Answers

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