Neighborhood Hardware is a hardware store It orders inventor

Neighborhood Hardware is a hardware store. It orders inventory from various distributors. Neighborhood Hardware gives each distributor a DistID.

Distributors may carry the same product. Each product has a universal UPC Number and product name. However, each distributor has their own in-house distributor product ID (dist_prod_id) for products they carry. For instance, Stanley Hammer-Pro has a universal UPC code 9785600021. Acer Inc. would refer to it by its product ID 576-183, HardwareKing would identify it as 4178BBR.

Each purchase order has a purchase order date, and it is issued to one distributor. Neighborhood Hardware can purchase multiple products on a purchase order, each product has a purchase quantity.

1) Identify a candidate key.

2) Identify all Functional Dependency in the format of A -> B, C

DistIDDistName DistProdID UPCNumber ProdName Qty PurOrd PurOrd Num 25278 03/12/12 101 Date 9785600001 Screwdriver 9785600016 Handsaw 9785600007 Bolt cutter 9785600021 Stanley Hammer-Pro2 9785600023 Chain saw, 16 in. 9785600007 Bolt cutter 9785600015 2.75 in. bolt, 12 9785600016 Handsaw 9785600001 Screwdriver 9785600023 Chain saw, 16 in. 9785600021 9785600007 Bolt cutter 9785600007 Bolt cutter 9785600023 Chain saw, 16 in. 9785600015 2.75 in. bolt, 12 9785600021 Stanley Hammer-Pro3 9785600023 Chainsaw, 16 in 576-101 576-112 576-109 576-183 Acer Inc. 25279 03/12/12 102 DOIT Distribution 0-345111 0-345115 4-896101 3-896102 152 BGR 177 BXR 178 BBR 12 2528103/13/12 103 HardwareKing Stanley Hammer-Pro 1 4 102 DOIT Distribution 0-345115 DOIT Distribution 0-345115 03/13/12 25282 25283 03/14/12 102 0-345111 4-896101 4178 BBR 4177 BXR 25284 03/14/12 103 HardwareKing

Solution

1. X is candidate key iff :

a - No two records whose value is same.

b - Any proper subset shout not able differenciate records uniquely.

So, PurOrdNum is candidate candidate keys because no two records have the same value.

2. Functional dependency {A ->B} : For each A value there must be single B value .

PurOrdNum -> PurOrdDate

PurOrdNum -> DisID

PurOrdNum -> DisName

PurOrdNum ->DisProductID

PurOrdNum ->UPCNum

PurOrdNum ->UPCName

PurOrdNum ->Qty

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