By having only one table it sounds like you are using Access more like a
spreadsheet than a database, hence the repetitive data.
The classic way of modelling a bill of materials is to have two tables, one
of Parts. Each assembly or sub-assembly is included in this table as well as
base parts, so it might look like this:
PartNum PartName Weight
1 Assembly 1 0
2 Assembly 2 0
3 Assembly 3 0
4 Assembly 4 0
5 Assembly 5 0
6 Part 1 10
7 Part 2 5
Then a PartStructure table references the PartNum column of the above table
in Majorpart and MinorPart columns like so:
MajorPartNum MinorPartNum Quantity
1 2 2
1 3 3
2 3 4
2 4 2
3 4 1
3 5 2
4 5 3
5 6 2
5 7 1
Your newsreader may well have screwed up the alignment of the above, but I
hope you can see what its doing, e.g. assembly 1 is made up of assemblies 2
and 3, assembly 2 of assemblies 3 and 4 and so on.
Data such as drawing numbers would do in another table related to the Parts
table by PartNum (if each drawing relates to one assembly only), or by a
further table to model the many-to-many relationship if a drawing relates to
multiple assemblies. Whichever is the case the repetitive data is avoided
and the tables are thus normalized.
You'll find a simple demo from which the above data is taken at:
http://community.netscape.com/n/pfx/forum.aspx?tsn=1&nav=messages&webtag=ws-msdevapps&tid=23133
The file is attached to the second post in the thread.
Ken Sheridan
Stafford, England