Customer$/$Product database modeling

Things to consider:

Purchase order $($PO$)$: is a legal document "Contract" issued by the buyer $($customer$)$ to the supplier,

indicating specifications, quantities, shipping date & mode, prices and agreed terms and conditions.

Invoice: is a document issued by a supplier $($Vendor$)$ to a customer. It identifies both parties and, it

shows the description, quantities, prices shipment date & mode and the payment terms of the items

sold. It serves as a demand for payment if it issued after the PO legalized or it may be just a pro$-$

forma invoice.

Many Invoices maybe generated for a single PO$!$

Sample of PO and Invoice forms are included.

Part $1($Invoice DB$).$

Identify entities in invoice transaction

Identify entities' identifier

Identify business rules $($make assumption wherever is necessary$)$

Draw invoice ERD and add necessary and sufficient attributes to each entity

Part $2($PO DB$).$

Identify entities in PO transaction

Identify entities' identifier

Identify business rules $($make assumption wherever is necessary$)$

Draw PO ERD and add necessary and sufficient attributes to each entity

Bonus

Draw the ERD of the PO and Invoice database as a single database system $($consider you are designing

the customer database$)$

$[$Company Name$]$ INVOIGE

$[$Street Address$),[$City$,$ st ZIP Code$][$Phone: $555-555-55555]$ IF

$[$Phone: $555-555-55555][$Fax: $123-123-123456][$abc@example.com$]$

Billed To:

$[$Company Name$]$

$[$Your Company Slogan$]$

$[$Street Address$]$

$[$City$,$ ST Z$1$P Code$]$ Phone $[(212)444-0123]$ Fax $[(212)444-0144]$

The following number must appear on all related

correspondence, shipping P$.$O$.$ NUMBER: $[001]$

Please send two copies of your invoice.

Enter this order in accordance with the prices, terms, delivery method, and specifications listed above.

Please notify us immediately if you are unable to ship as specified.

Send all correspondence to:

$[$Name$][$Street Address$][$City$,$ ST ZIP CO

$[$City$,$ ST ZIP Code$]$ Phone $[(212)444-0123]$ Fax $[(212)444-0144]$

PURCHASE ORDER

SHIPPING & HANDUNG

OTHER

TOTAL