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Opinions on Equipment Database
Old 01-24-2008, 03:14 PM Opinions on Equipment Database
Junior Talker

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Name: Erik Jenson
Hello. I am looking for opinions on the best set up of the equipment porion of a larger database. Unfortunately we are limited to MS Access.

The Whole database will include Equipment, Location of equipment. Wiring from/to equipment. and the finer details of each (connector type, port names, cable colour etc.)

Basically I am wondering how to deal with the equipmnet. There are several different manufacturers and configurations. Should I have a table for each piece of equipment or simply size the table for the one with the most ports (150 possible columns of data - some equipment needs only 5 or 6)

Anyone have any thoughts?
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Old 01-24-2008, 09:13 PM Re: Opinions on Equipment Database
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Quote:
simply size the table for the one with the most ports (150 possible columns of data - some equipment needs only 5 or 6)
Absolutely NOT!!!

Create your structures to minimise duplicate data and redundant columns.
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Old 01-25-2008, 09:19 AM Re: Opinions on Equipment Database
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Name: Erik Jenson
So to be clear, it sounds like the recommendation is to make a table large enough for the biggest number of ports required by any piece of equipment. Eventhough some components will only use 5 out of 150 possible datafields. And populate that table with the details of each piece of equipment in the system. Does that sound right?
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Old 01-25-2008, 08:14 PM Re: Opinions on Equipment Database
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No.

make a table of devices and a table of ports and use a PK / FK relationship

so 1 device may have 5 matching records in ports another may have 24 and other ones may have 100 or more.
BUT the ports table only ever needs "x" columns deviceID, portNo, Destination_Device, Cable_Colour, Cable_Size, Cable_Designation for example

device table needs ID, Manufact, Model, SerialNo, Ports, LocationID, etc etc

Locations = ID, ShortName, Description etc

if you need to use ANY data more that twice use a separate table and join on IDs. It's a process called "normalisation"
It makes the database smaller with less redundant data and can make queries MUCH quicker.
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