Reference for Question 1 Sales Database: Customer(custId, lastName, firstName, a

Question

Reference for Question 1

Sales Database:

Customer(custId, lastName, firstName, address, phone, creditLimit)

Order(orderNumber, date, total, custId)

LineItem(orderNumber, itemNumber, qtyOrdered)

Item(itemNumber, itemName, price)

For the Sales Database in the reference, write the relational algebra expression for the query

Find the lastName of the customer for orderNumber 12345.

Reference for Question 2

Sales Database:

Customer(custId, lastName, firstName, address, phone, creditLimit)

Order(orderNumber, date, total, custId)

LineItem(orderNumber, itemNumber, qtyOrdered)

Item(itemNumber, itemName, price)

For the Sales Database in the reference, write the relational algebra expression for the query "Find the names and quantities of all items on order 12345."

Explanation / Answer

Q1.

SELECT c.lastName

FROM Customer c, Order o

WHERE

c.CustId = o.CustId

AND

o.orderNumber = 12345;

Q2.

SELECT i.itemName, l.qtyOrdered

FROM Item i, LineItem l

WHERE

i.itemNumber = l.itemNumber

AND

l.orderNumber = 12345;

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