1. Certification for the module on the relational model

2. Question – part 1
The following relational schema refers to a retail chain, namely a group of retail stores (or outlets) that share a brand and central management, and usually have standardized business methods and practices. Every store has one store manager and several employees, the same employee can be the manager of different stores. Suppliers delivery items to stores in certain dates. Customers receive Store-Receipts that list items sold to the Customer in Stores.

3. Question – part 2
Store (Store-Id, Address, City, Telephone number, Web address, address, Store-Manager-Id) 
Effort-of-Store-Manager (Store-Manager-Id, Store-Id, %-of-time)
Employee (Employee-Id, SocialSecurityNumber, First Name, Last Name, Telephone number, Store-Id)
Supplier (Vat-Id, Name-of-Supplier, Address, Telephone number)
Item-of-Delivery (Item-Code, Price, Type-of-Item, Item-Description)
Delivery (Store-Id, Item-Code, Date, Number-of-Items, Supplier)
Receipt (Receipt-Number, Store-Id, Clerk, Date, Total Price)
Receipt-Item (Receipt-Number, Store-Id, Item-Code, Number-of-Items, Total- Price)

4. Question part 3 – Focus on keys
Look at the following form and for each relation schema (e.g. Store) mark the attribute or the set of attributes that form the primary key.

5. First question: solution#
Relation
Maximum score 1
Supplier 8 2
Employee 12 3
Item-of-Delivery 4
Store 5
Effort-of-Store-Manager 6
Receipt 24 7
Receipt-Item
Delivery 16

6. Questions on Keys (in red the relation object of the question)
Supplier (Vat-Id, , Telephone number, Name-of-Supplier, Address)
Employee (Telephone number, Employee-Id, SocialSecurityNumber, First Name, Last Name, Store- Id)
Item-of-Delivery (Item-Code, Price, Type-of-Item, Item-Description)
Store (Store-Id, Address, City, Telephone number, Web address, address, Store-Manager- Id) 
Effort-of-Store-Manager (Store-Manager-Id, Store-Id, %-of-time)
Receipt (Receipt-Number, Store-Id, Clerk, Date, Total Price)
Receipt-Item (Receipt-Number, Store-Id, Item-Code, Number-of-Items, Total-Price)
Delivery (Store-Id, Item-Code, Date, Number-of-Items, Supplier)
Choose among the following possible Primary Keys
Score
Vat-Id, Telephone number 3
Name-of-Supplier
Vat-Id 8
Telephone number 6

7. Questions on Keys (in red the Relation object of the question)
Supplier (Vat-Id, , Telephone number, Name-of-Supplier, Address)
Employee (Telephone number, Employee-Id, SocialSecurityNumber, First Name, Last Name, Store-Id)
Item-of-Delivery (Item-Code, Price, Type-of-Item, Item-Description)
Store (Store-Id, Address, City, Telephone number, Web address, address, Store-Manager- Id) 
Effort-of-Store-Manager (Store-Manager-Id, Store-Id, %-of-time)
Receipt (Receipt-Number, Store-Id, Clerk, Date, Total Price)
Receipt-Item (Receipt-Number, Store-Id, Item-Code, Number-of-Items, Total-Price)
Delivery (Store-Id, Item-Code, Date, Number-of-Items, Supplier)
Choose among the following possible Primary Keys
Score
Telephone number 3
SocialSecurityNumber3 10
Employee-Id 12
EmployeeId, SocialSecurityNumber 6
First Name, Last Name

8. Questions on Keys (in red the Relation object of the question)
Supplier (Vat-Id, , Telephone number, Name-of-Supplier, Address)
Employee (Telephone number, Employee-Id, SocialSecurityNumber, First Name, Last Name, Store- Id)
Item-of-Delivery (Item-Code, Price, Type-of-Item, Item-Description)
Store (Store-Id, Address, City, Telephone number, Web address, address, Store-Manager- Id) 
Effort-of-Store-Manager (Store-Manager-Id, Store-Id, %-of-time)
Receipt (Receipt-Number, Store-Id, Clerk, Date, Total Price)
Receipt-Item (Receipt-Number, Store-Id, Item-Code, Number-of-Items, Total-Price)
Delivery (Store-Id, Item-Code, Date, Number-of-Items, Supplier)
Choose among the following possible Primary Keys
Score
Type-of-Item
Item-Code 8
Item-Code, Type-of-Item 3
Item-Code, Price

9. Questions on Keys (in red the Relation object of the question)
Supplier (Vat-Id, , Telephone number, Name-of-Supplier, Address)
Employee (Telephone number, Employee-Id, SocialSecurityNumber, First Name, Last Name, Store- Id)
Item-of-Delivery (Item-Code, Price, Type-of-Item, Item-Description)
Store (Store-Id, Address, City, Telephone number, Web address, address, Store-Manager- Id) 
Effort-of-Store-Manager (Store-Manager-Id, Store-Id, %-of-time)
Receipt (Receipt-Number, Store-Id, Clerk, Date, Total Price)
Receipt-Item (Receipt-Number, Store-Id, Item-Code, Number-of-Items, Total-Price)
Delivery (Store-Id, Item-Code, Date, Number-of-Items, Supplier)
Choose among the following possible Primary Keys
Score
Store-Manager-Id
Store-Id 8
Web address 5
address

10. Questions on Keys (in red the Relation object of the question)
Supplier (Vat-Id, , Telephone number, Name-of-Supplier, Address)
Employee (Telephone number, Employee-Id, SocialSecurityNumber, First Name, Last Name, Store- Id)
Item-of-Delivery (Item-Code, Price, Type-of-Item, Item-Description)
Store (Store-Id, Address, City, Telephone number, Web address, address, Store-Manager- Id) 
Effort-of-Store-Manager (Store-Manager-Id, Store-Id, %-of-time)
Receipt (Receipt-Number, Store-Id, Clerk, Date, Total Price)
Receipt-Item (Receipt-Number, Store-Id, Item-Code, Number-of-Items, Total-Price)
Delivery (Store-Id, Item-Code, Date, Number-of-Items, Supplier)
Choose among the following possible Primary Keys
Score
Store-Manager-Id 5
Store-Manager-Id, %-of-time 4
Store-Manager-Id, Store-Id 12
Store-Id

11. Questions on Keys (in red the Relation object of the question)
Supplier (Vat-Id, , Telephone number, Name-of-Supplier, Address)
Employee (Telephone number, Employee-Id, SocialSecurityNumber, First Name, Last Name, Store- Id)
Item-of-Delivery (Item-Code, Price, Type-of-Item, Item-Description)
Store (Store-Id, Address, City, Telephone number, Web address, address, Store-Manager- Id) 
Effort-of-Store-Manager (Store-Manager-Id, Store-Id, %-of-time)
Receipt (Receipt-Number, Store-Id, Clerk, Date, Total Price)
Receipt-Item (Receipt-Number, Store-Id, Item-Code, Number-of-Items, Total-Price)
Delivery (Store-Id, Item-Code, Date, Number-of-Items, Supplier)
Choose among the following possible Primary Keys
Score
Store-Receipt-Number, Store-Id 12
Store-Receipt-Number 4
Store-Receipt-Number, Clerk 5
Clerk, Date
Store-Id, Date

12. Questions on Keys (in red the Relation object of the question)
Supplier (Vat-Id, , Telephone number, Name-of-Supplier, Address)
Employee (Telephone number, Employee-Id, SocialSecurityNumber, First Name, Last Name, Store- Id)
Item-of-Delivery (Item-Code, Price, Type-of-Item, Item-Description)
Store (Store-Id, Address, City, Telephone number, Web address, address, Store-Manager- Id) 
Effort-of-Store-Manager (Store-Manager-Id, Store-Id, %-of-time)
Receipt (Receipt-Number, Store-Id, Clerk, Date, Total Price)
Receipt-Item (Receipt-Number, Store-Id, Item-Code, Number-of-Items, Total-Price)
Delivery (Store-Id, Item-Code, Date, Number-of-Items, Supplier)
Choose among the following possible Primary Keys
Score
Store-Receipt-Number
Store-Receipt-Number, Store-Id, Number-of-Items 5
Store-Receipt-Number, Store-Id, Item-Code 12
Store-Receipt-Number, Item-Code 9

13. Questions on Keys (in red the Relation object of the question)
Supplier (Vat-Id, , Telephone number, Name-of-Supplier, Address)
Employee (Telephone number, Employee-Id, SocialSecurityNumber, First Name, Last Name, Store- Id)
Item-of-Delivery (Item-Code, Price, Type-of-Item, Item-Description)
Store (Store-Id, Address, City, Telephone number, Web address, address, Store-Manager- Id) 
Effort-of-Store-Manager (Store-Manager-Id, Store-Id, %-of-time)
Receipt (Receipt-Number, Store-Id, Clerk, Date, Total Price)
Receipt-Item (Receipt-Number, Store-Id, Item-Code, Number-of-Items, Total-Price)
Delivery (Store-Id, Item-Code, Date, Number-of-Items, Supplier)
Choose among the following possible Primary Keys
Score
Store-Id, Number-of-Items
Item-Code, Date 10
Store-Id, Item-Code, Date 14
Store-Id, Item-Code, Date, Supplier 24
Item-Code, Date, Supplier

14. Second question – Referential Integrity Constraints
First of all, look carefully at the following correct solution to the previous question
Store (Store-Id, Address, City, Telephone number, Web address, address, Store-Manager-Id) 
Effort-of-Store-Manager (Store-Manager-Id, Store-Id, %-of-time)
Employee (Employee-Id, SocialSecurityNumber, First Name, Last Name, Telephone number, Store-Id)
Supplier (Vat-Id, Name-of-Supplier, Address, Telephone number)
Item-of-Delivery (Item-Code, Price, Type-of-Item, Item-Description)
Delivery (Store-Id, Item-Code, Date, Number-of-Items, Supplier)
Receipt (Receipt-Number, Store-Id, Clerk, Date, Total Price)
Receipt-Item (Receipt-Number, Store-Id, Item-Code, Number-of-Items, Total- Price)

15. Second question Identify Referential integrity constraints defined among pairs of relations, and their number of occurrences (if you do not fill the cell, this means 0)
Store (Store-Id, Address, City, Telephone number, Web address, address, Store-Manager-Id) 
Effort-of-Store-Manager (Store-Manager-Id, Store-Id, %-of-time)
Employee (Employee-Id, SocialSecurityNumber, First Name, Last Name, Telephone number, Store-Id)
Supplier (Vat-Id, Name-of-Supplier, Address, Telephone number)
Item-of-Delivery (Item-Code, Price, Type-of-Item, Item-Description)
Delivery (Store-Id, Item-Code, Date, Number-of-Items, Supplier)
Store-Receipt (Store-Receipt-Number, Store-Id, Clerk, Date, Total Price)
Store-Receipt-Item (Store-Receipt-Number, Store-Id, Item-Code, Number-of-Items, Total-Price) #Z
Store
Effort-of-Store-Manager
Store-Employee
Supplier
Item
Delivery
Receipt
Receipt-Item 1 2 3
Employee 4 5 6 7 8
From To 

16. Solution to the second question
Store (Store-Id, Address, City, Telephone number, Web address, address, Store-Manager-Id) 
Effort-of-Store-Manager (Store-Manager-Id, Store-Id, %-of-time)
Employee (Employee-Id, SocialSecurityNumber, First Name, Last Name, Telephone number, Store-Id)
Supplier (Vat-Id, Name-of-Supplier, Address, Telephone number)
Item-of-Delivery (Item-Code, Price, Type-of-Item, Item-Description)
Delivery (Store-Id, Item-Code, Date, Number-of-Items, Supplier)
Receipt (Receipt-Number, Store-Id, Clerk, Date, Total Price)
Receipt-Item (Receipt-Number, Store-Id, Item-Code, Number-of-Items, Total-Price) #Z
Store
Effort-of-Store-Manager
Store-Employee
Supplier
It0em
Delivery
Receipt
Receipt-Item 1 2 3
Employee 4 5
Item 6 7 8
From To 

17. Scores assigned to correct Integrity constraints
Store (Store-Id, Address, City, Telephone number, Web address, address, Store-Manager-Id) 
Effort-of-Store-Manager (Store-Manager-Id, Store-Id, %-of-time)
Employee (Employee-Id, SocialSecurityNumber, First Name, Last Name, Telephone number, Store-Id)
Supplier (Vat-Id, Name-of-Supplier, Address, Telephone number)
Item-of-Delivery (Item-Code, Price, Type-of-Item, Item-Description)
Delivery (Store-Id, Item-Code, Date, Number-of-Items, Supplier)
Receipt (Receipt-Number, Store-Id, Clerk, Date, Total Price)
Receipt-Item (Receipt-Number, Store-Id, Item-Code, Number-of-Items, Total-Price)
#  1 2 3 4 5 6 7 8 #
Store
Effort-of-Store-Manager
Store-Employee
Supplier
Item
Delivery
Receipt
Receipt-Item 9
Employee 15 25
From To 

18. Procedure for the total score
If Solution(1,3) = StudentSolution(1,3) then Total-score = Total-score + 9
If Solution(3,1) = StudentSolution(3,1) then Total-score = Total-score + 15
If Solution(6,1) = StudentSolution(6,1) then Total-score = Total-score + 9
If Solution(6,4) = StudentSolution(6,4) then Total-score = Total-score + 15
If Solution(6,5) = StudentSolution(6,5) then Total-score = Total-score + 9
If Solution(7,1) = StudentSolution(7,1) then Total-score = Total-score + 9
If Solution(7,4) = StudentSolution(7,4) then Total-score = Total-score + 9
If Solution(8,7) = StudentSolution(8,7) then Total-score = Total-score + 25

19. Simplified procedure for the total score 27/03/2018
If StudentSolution(1,3) = 1 then Total-score = Total-score + 9
If StudentSolution(3,1) = 1 then Total-score = Total-score + 15
If StudentSolution(6,1) = 1 then Total-score = Total-score + 9
If StudentSolution(6,4) = 1 then Total-score = Total-score + 15
If StudentSolution(6,5) = 1 then Total-score = Total-score + 9
If StudentSolution(7,1) = 1 then Total-score = Total-score + 9
If StudentSolution(7,4) = 1 then Total-score = Total-score + 9
If StudentSolution(8,7) = 1 then Total-score = Total-score + 25

20. Left over

21. Referential integrity constraints – correct solution
Store (Store-Id, Address, City, Telephone number, Web address, address, Store-Manager-Id) 
Effort-of-Store-Manager (Store-Manager-Id, Store-Id, %-of-time)
Store-Employee (Employee-Id, SocialSecurityNumber, First Name, Last Name, Telephone number, Store-Id)
Supplier (Vat-Id, Name-of-Supplier, Address, Telephone number)
Item (Item-Code, Price, Type-of-Item, Item-Description)
Delivery (Store-Id, Item-Code, Date, Number-of-Items, Supplier)
Store-Receipt (Store-Receipt-Number, Store-Id, Employee, Date, Total Price)
Store-Receipt-Item (Store-Receipt-Number, Store-Id, Item-Code, Number-of- Items, Total-Price)