2nd post Database design different attributes

[Burghew]

Hi all,

Kindly help me out on this one. I am having a computer shop and we have many
IT related equipments nearly 30 categories which comprises of Servers,
Laptops, PC's, Printers, routers, switches, monitors, Software etc...
Now each of the aboved mentioned category have different attributes such as
Servers may have different configuration like raid, SCSI Hdd, etc, Laptops
may have different attributes from that of PC's, similarly printers, scanner
and monitors have different attributes which are in no way related.

Output needed :
a) To maintain and track all the IT equipment which includes warranty etc
for all the equipments.
b) To check on support/service of equipments when I hand them over for
repair for example.
c) To generate invoices for customers who take or rent stuff from us.

Design
I tried to design this by keeping the following tables
A)
1) tblManufacturers -- Includes all the manufacturer details eg: HP, ACER,
etc
2) tblSuppliers -- Includes all our supplier information.
3) tblAssetCategories -- Includes all the nearly 30 above mentioned eg:
Laptop, Servers, Printers, Monitors, etc.
4) tblCommonAttributes -- Make, Serial No, Warranty Info, Purchasedate,
Purchasecost, etc
5) tblComputer -- Casing, Floppy, USB, MotherBoard, Processor, RAM, etc
6) tblServer -- RaidController, SCSI Type, TapeDrive etc
7) tblLaptop -- battery type, LCD screen type, Touch pad,
8) tblLaserPrinter -- PPM, RAM, trays, etc
9) tblDeskjet -- Catridges details etc.
similarly for the each asset tblRouter, TblSwitch with their attributes.
B)
tblCustomer --contains customer details
tbltransactions --contains details of all the transactions carried out
Related in 1 -- Many -- 1 with AssetID (obtained from the various tables)
C)
tblServiceRelated --- Conatins Items which are under repair/service.
tblScrap -- Items that need to de disposed
I also thought of trying to use One to One relation but that just adds up to
the confusion.

Problem area:
1) How can I link the Primary Key*s* from all the various tables such as
tblComputer which has PK AssetID for every computer
and also from tblLaptops (PK AssetID) , tblMonitors(PK AssetID) ,
tblPrinters (PK AssetID) , etc into the tblTransactions?
Also, I need to have select AssetID when I send them out for service or
to Scrap.

2) If I rent out certain equipment to any customer and if that equipment is
faulty we take it down to repair and assign him another one
till the equipment is fixed and returned and we do not charge him for
that much period for that month. Any Ideas please.

Please do let me know if my approach is correct and if any changes need to
be done. Awaiting eagerly for your replies thanks in advance.
--
Regards,
B

[Matthias Klaey]

"Burghew" <no****@sorry.com> wrote:

Hi all,

Kindly help me out on this one. I am having a computer shop and we have many
IT related equipments nearly 30 categories which comprises of Servers,
Laptops, PC's, Printers, routers, switches, monitors, Software etc...
Now each of the aboved mentioned category have different attributes such as
Servers may have different configuration like raid, SCSI Hdd, etc, Laptops
may have different attributes from that of PC's, similarly printers, scanner
and monitors have different attributes which are in no way related.

Output needed :
a) To maintain and track all the IT equipment which includes warranty etc
for all the equipments.
b) To check on support/service of equipments when I hand them over for
repair for example.
c) To generate invoices for customers who take or rent stuff from us.

Design
I tried to design this by keeping the following tables
A)
1) tblManufacturers -- Includes all the manufacturer details eg: HP, ACER,
etc
2) tblSuppliers -- Includes all our supplier information.
3) tblAssetCategories -- Includes all the nearly 30 above mentioned eg:
Laptop, Servers, Printers, Monitors, etc.
4) tblCommonAttributes -- Make, Serial No, Warranty Info, Purchasedate,
Purchasecost, etc
5) tblComputer -- Casing, Floppy, USB, MotherBoard, Processor, RAM, etc
6) tblServer -- RaidController, SCSI Type, TapeDrive etc
7) tblLaptop -- battery type, LCD screen type, Touch pad,
8) tblLaserPrinter -- PPM, RAM, trays, etc
9) tblDeskjet -- Catridges details etc.
similarly for the each asset tblRouter, TblSwitch with their attributes.
B)
tblCustomer --contains customer details
tbltransactions --contains details of all the transactions carried out
Related in 1 -- Many -- 1 with AssetID (obtained from the various tables)
C)
tblServiceRelated --- Conatins Items which are under repair/service.
tblScrap -- Items that need to de disposed
I also thought of trying to use One to One relation but that just adds up to
the confusion.

[...]

Instead of tables tblComputer, tblServer, tblLaptop etc. I would
create one table tblAttributes with the fields

Category
AttributeName
AttributeValue

to store the attributes that are unique to each category.

HTH

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[Peter Hoyle]

Matthias Klaey wrote in message

Burghew wrote:

Kindly help me out on this one. I am having a computer shop and we have
many
IT related equipments nearly 30 categories which comprises of Servers,
Laptops, PC's, Printers, routers, switches, monitors, Software etc...
Now each of the aboved mentioned category have different attributes such
as
Servers may have different configuration like raid, SCSI Hdd, etc, Laptops
may have different attributes from that of PC's, similarly printers,
scanner
and monitors have different attributes which are in no way related.

Output needed :
a) To maintain and track all the IT equipment which includes warranty etc
for all the equipments.
b) To check on support/service of equipments when I hand them over for
repair for example.
c) To generate invoices for customers who take or rent stuff from us.

Instead of tables tblComputer, tblServer, tblLaptop etc. I would
create one table tblAttributes with the fields

Category
AttributeName
AttributeValue

to store the attributes that are unique to each category.

Matthias hit the nail on the head!

For the main tables you could expand on this (roughly)

tblCategories e.g. Laptop, Server etc.
tblAssets with common asset attributes plus foreign key from tblCategories
e.g. this asset is a Server.
tblCategoryAttribute lists the attributes that a category can take e.g.
Laptop, Screen Resolution.
tblAssetAttributes lists the specific attributes of a particular Asset
e.g. AssetID 9874, CategoryAttributeID 15 (Laptop Screen Resolution),
Value 1024x768

tblTransactionType e.g Rental, Repair
tblTransactions e.g AssetID 9874, CustomerID 12, TransactionType Rental,
StartDate 10/03/05, EndDate 10/09/05

etc,

--
peter
http://www.peterhoyle.co.uk