This question is in relation to my need for a hierarchical structured database for hardware parts with Assemblies / SubAssemblies / Components. I have been told by a MicroSoft Access Database MVP that I will have problems with:
"You're in trouble if they don't fit that pattern, e.g. if you have one that
looks like this:
or like this:
Yes, we have these hardware assembly types (as well as the three below) so I have stopped building the data for MS Access tables.
Has anyone seen examples of a database (and/or tables) structured for hardware assemblies and subassemblies?
A. Key database writers have pointed me towards Joe Celko's book "SQL
for Smarties." Mr Celko has written "TREES & HIERARCHIES IN SQL" due out in April 2004 from Morgan-Kaufmann publishers. (Published database literature on hardware assemblies seems to be almost nonexistant).
B. Key terms in this search:
Bill Of Materials or BOM
trees, tree structure
C. Description of problem:
I am/was building tables for a new MS Access 2000 DB to control hardware data
for rod assemblies (rods move landing gear doors, ailerons, rudders, cargo
doors) for aircraft.
So a typical comparison of two would look like AssemblyE and AssemblyF below
(breaks down into 2 sub-levels).
And an extreme example would look like AssemblyRodG below (breaks down into
3 sub-levels, but we could anticipate 4 sub-levels).
(So far, I have compiled the data into 3 tables: Assemblies, SubAssemblies,
you issue is more or less one of object oriented design and parent objects (trust me). If you go to the microsoft office website you can down load a sample database that allows you to track family tree's. It may help.