ASSIGNMENT FINAL REPORT

Qualification Pearson BTEC Level 5 Higher National Diploma in Computing

Unit number and title Unit 4: Database Design & Development

Submission date Date Received 1st submission

Re-submission Date Date Received 2nd submission

Student Name Pham Quang Huy Student ID BD00564

Class SE07202 Assessor name Nguyen Viet Luan

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Table of content
Table of Figure
 Introduction
 This project focuses on designing and implementing a database system tailored for a retail store
to handle its core functions. The database is structured to support various business operations,
including product management, employee management, customer management, sales tracking,
and reporting. With clearly defined relationships between entities, the system ensures that data
is stored systematically and is accessible for analysis and decision-making.
CHAP I. Use an appropriate design tool to design a relational database
system for a substantial problem ( LO1)
1. Design a relational database system using appropriate design tools and
techniques, containing at least four interrelated tables, with clear statements of
user and system requirements (P1).
1.1 Identify the problem to be solved by the relational database management system.
 The primary goal of the RDBMS for Store X is to establish a reliable and efficient Sales
Management System that will streamline and enhance key business processes, ensuring
seamless operations across multiple areas, including:
 Product Management
o Data Storage and Retrieval: Maintain comprehensive product information, including product
codes, names, prices, descriptions, and inventory levels.
o Accounting Operations: Supports adding, modifying, and deleting product records.
o Inventory Management: Provides real-time updates on inventory levels after sales or
warehousing activities.
o Product Images: Manage product images to support sales and marketing efforts.
 Employee Management
o Employee Profiles: Store detailed employee information, including roles, contact
information, and access rights.
o User Accounts: Facilitate user account creation with secure login processes, requiring a
mandatory password change upon first use.
o Role-Based Access Control: Assign appropriate permissions to roles such as administrator,
salesperson, and warehouse worker.
 Customer Management
o Customer Data: Maintain a database of customer details, including name, contact
information, and purchase history.
o CRUD Functionality: Enable full functionality to create, read, update, and delete customer
records to ensure data accuracy.
 Sales Statistics and Reporting
o Performance Insights: Generate key KPIs, including total sales revenue, profit margins, and
sales metrics by product or time frame (daily, monthly, yearly).
o Operations Monitoring: Track inventory intake and evaluate employee performance metrics.
o Strategic Reporting: Generate detailed reports to inform decision making and strategic
planning.
 Security Management
o Access Control: Implement strict role-based access rights to protect sensitive business
information.
o Secure Login: Incorporate features like password encryption and multi-factor authentication
to enhance login security.
 Data Protection: Ensure all data stored complies with relevant data protection regulations and
standards, protecting against unauthorized access or breaches.

1.2 Design tables of entities and properties related to the problem:

 Customer Table :

Customer
PK ID_Customer char(10)
Name_Customer varchar(50)
Sex nvarchar(50)
Address nvarchar(50)
PHONE varchar(50)
Figure 1 : Customer table

 Staff Table
STAFF
PK ID_Staff char(10)
Name_Staff varchar(50)
Sex nvarchar(50)
Phone varchar(15)
Address nvarchar(50)
Figure 2 : Staff
 Product Table

Product
PK ID_Product char(10)
Name_Product varchar(50)
ID_Supplier char(10)
Quantity int
Price int
Figure 3 : Product

 In addition, I also created 3 more tables, Import_Invoice, Supplier and Sales_Invoice, for easy
use and application management.
 Import_Invoice Table

Import_Invoice
PK ID_Invoice char(10)
ID_Staff char(10)
ID_Product char(10)
 ID_Supplier char(10)
Quantity Int
Date_of_Sale date
Address varchar(50)
PHONE varchar(15)
Unit_Price float
Total_Money float
Figure 5 : Import_Invoice

 Supplier Table

Supplier
PK ID_Supplier char(10)
Name_Supplier varchar(50)
Address nvarchar(50)
PHONE varchar(15)

Figure 6 : Supplier
 Sales_Invoice Table

Sales_Invoice
PK ID_Sales_Invoice char(10)
ID_Staff char(10)
ID_Product char(10)
ID_Customer char(10)
Quantity Int
Date_of_Sale date
Address varchar(50)
PHONE varchar(15)
Unit_Price float
Total_Money float

1.3 Draw an Entity-Relationship Diagram (ERD) to illustrate the entities and the
relationships between them:
 An Entity Relationship Diagram (ERD) is a fundamental tool in database design, serving as a
structural representation of an organization's data. It visually depicts the relationships between
 "entities"—which can include people, objects, events, or concepts—and how they interact
within the system.
 The key purposes of an ERD include:
 Database Design: Providing a clear, visual foundation for designing databases by identifying
entities, their attributes, and the relationships between them.
 Requirement Definition: Helping to capture and define the data requirements of an
organization's information system.
 Collaboration Tool: Facilitating communication among stakeholders, including developers,
analysts, and business teams, to ensure a shared understanding of system requirements.
 Problem Identification: Identifying potential gaps or inconsistencies in the data model before
implementation.

Figure 7 : ERD
  Physical design: The design adapted to the RDBMS and system constraints and features. After
we design the logical of user requirement, we implementing the physical design by SQL server.

1.4 Design the tables needed in the database, the columns corresponding to
the attributes, and the data type for each column.

 CUSTOMER :

Figure 8 : CUSTOMER
 PRODUCT :

Figure 9 : PRODUCT
 STAFF :

Figure 10 : STAFF
 Import_Invoice:

Figure 11 : Import_Invoice

 Sales_Invoice

Figure 12 : Sales_Invoice
 Supplier
1.5 Set up primary keys and foreign keys to ensure data integrity.
 Entities and Attributes:
 Supplier
o Entity Description: Represents suppliers who provide products to the store.
o Attributes:
 ID_Supplier (CHAR(10)): Primary key, unique identifier for each supplier.
 Name_Supplier (VARCHAR(50)): The name of the supplier.
 Address (NVARCHAR(50)): The address of the supplier.
 PHONE (VARCHAR(15)): The contact number of the supplier
 Product
o Entity Description: Represents products available for sale or purchase in the store.
o Attributes:
 ID_Product (CHAR(10)): Primary key, unique identifier for each product.
 Name_Product (VARCHAR(50)): The name of the product.
 ID_Supplier (CHAR(10)): Foreign key referencing Supplier(ID_Supplier), indicating
which supplier provides the product.
 Quantity (INT): The available stock quantity of the product.
 Price (INT): The price of the product.
 Staff
o Entity Description: Represents the employees of the store.
o Attributes:
 ID_Staff (CHAR(10)): Primary key, unique identifier for each staff member.
 Name_Staff (VARCHAR(50)): The name of the staff member.
 Sex (NVARCHAR(50)): The gender of the staff member.
 Address (NVARCHAR(50)): The address of the staff member.
 PHONE (VARCHAR(15)): The contact number of the staff member.
 Customer
o Entity Description: Represents customers who make purchases.
o Attributes:
 ID_Customer (CHAR(10)): Primary key, unique identifier for each customer.
 Name_Customer (VARCHAR(50)): The name of the customer.
  Sex (NVARCHAR(50)): The gender of the customer.
 Address (NVARCHAR(50)): The address of the customer.
o PHONE (VARCHAR(15)): The contact number of the customer
 Import_Invoice
o Entity Description: Represents invoices for importing products into inventory.
Attributes:
 ID_Invoice (CHAR(10)): Primary key, unique identifier for each import invoice.
 ID_Staff (CHAR(10)): Foreign key referencing Staff(ID_Staff), indicating the staff
member handling the import.
 ID_Product (CHAR(10)): Foreign key referencing Product(ID_Product), indicating the
product being imported.
 ID_Supplier (CHAR(10)): Foreign key referencing Supplier(ID_Supplier), indicating the
supplier of the imported product.
 Quantity (INT): Quantity of the product being imported.
 Date_of_Sale (DATE): Date of the import transaction.
 Address (VARCHAR(50)): Address for the delivery or transaction.
 PHONE (VARCHAR(15)): Contact number related to the transaction.
 Unit_Price (FLOAT): The unit price of the imported product.
 Total_Money (FLOAT): The total value of the import transaction.
 Sales_Invoice
o Entity Description: Represents invoices for products sold to customers.
o Attributes:
 ID_Sales_Invoice (CHAR(10)): Primary key, unique identifier for each sales invoice.
 ID_Staff (CHAR(10)): Foreign key referencing Staff(ID_Staff), indicating the staff
member handling the sale.
 ID_Customer (CHAR(10)): Foreign key referencing Customer(ID_Customer), indicating
the customer making the purchase.
 ID_Product (CHAR(10)): Foreign key referencing Product(ID_Product), indicating the
product being sold.
 Quantity (INT): Quantity of the product being sold.
 Date_of_Sale (DATE): Date of the sale transaction.
 Address (VARCHAR(50)): Address for the delivery or transaction.
 PHONE (VARCHAR(15)): Contact number related to the transaction.
 Unit_Price (FLOAT): The unit price of the product sold.
 Total_Money (FLOAT): The total value of the sales transaction.
 Relationships
 Supplier ↔ Product: A supplier provides products (Product.ID_Supplier references
Supplier.ID_Supplier).
 Staff ↔ Import_Invoice: Staff handle imports (Import_Invoice.ID_Staff references
Staff.ID_Staff).
  Product ↔ Import_Invoice: Products are imported via invoices (Import_Invoice.ID_Product
references Product.ID_Product).
 Customer ↔ Sales_Invoice: Customers make purchases (Sales_Invoice.ID_Customer
references Customer.ID_Customer).
 Staff ↔ Sales_Invoice: Staff process sales (Sales_Invoice.ID_Staff references Staff.ID_Staff).
 Product ↔ Sales_Invoice: Products are sold via invoices (Sales_Invoice.ID_Product references
Product.ID_Product).
1.5.1 Supplier - Product
 Relationship: 1-N (One supplier supplies many products).
 Foreign Key: The ID_Supplier column in the Product table is a foreign key that references the
ID_Supplier column in the Supplier table.
 Action:
 ON DELETE CASCADE: Deleting a supplier will automatically delete related products.
 ON UPDATE CASCADE: If the ID_Supplier is updated, the related products will be
automatically updated.
1.5.2 Staff - Import_Invoice:
 Relationship: 1-N (One staff can create multiple import invoices).
 Foreign Key: The ID_Staff column in the Import_Invoice table is a foreign key that references
the ID_Staff column in the Staff table.
 Action:
 ON DELETE CASCADE: Deleting a staff will delete the import invoices that the staff
has created.
 ON UPDATE CASCADE: If the ID_Staff is updated, the related invoices will be updated
accordingly.
1.5.3 Supplier - Import_Invoice
 Relationship: 1-N (A supplier can be associated with multiple import invoices).
 Foreign Key: ID_Supplier column in Import_Invoice table references ID_Supplier in Supplier
table.
 Action:
 ON DELETE NO ACTION: Do not allow deleting supplier if there is a related import invoice.
 ON UPDATE NO ACTION: Do not allow updating ID_Supplier if there is a related import
invoice.
1.5.4 Product - Import_Invoice
 Relationship: 1-N (A product can be imported through multiple import invoices).
 Foreign Key: ID_Product column in Import_Invoice table references ID_Product in Product table.
 Action:
 ON DELETE CASCADE: Deleting product will delete related import invoices.
  ON UPDATE CASCADE: If ID_Product is updated, related import invoices will be updated
automatically..
1.5.5 Staff - Sales_Invoice
 Relationship: 1-N (One employee can create multiple sales invoices).
 Foreign Key: ID_Staff column in Sales_Invoice table references ID_Staff in Staff table.
 Action:
 ON DELETE CASCADE: Deleting employee will delete related sales invoices.
 ON UPDATE CASCADE: If ID_Staff is updated, related sales invoices will be updated
automatically..
1.5.6 Customer - Sales_Invoice
 Relationship: 1-N (A customer can purchase multiple sales invoices).
 Foreign Key: The ID_Customer column in the Sales_Invoice table references the ID_Customer
in the Customer table.
 Action:
 ON DELETE CASCADE: Deleting a customer will delete the related sales invoices.
 ON UPDATE CASCADE: If ID_Customer is updated, the related sales invoices will be
automatically updated..
1.5.7 Product - Sales_Invoice
 Relationship: 1-N (A product can appear in multiple sales invoices).
 Foreign Key: The ID_Product column in the Sales_Invoice table references the ID_Product in
the Product table.
 Action:
 ON DELETE CASCADE: Deleting a product will delete the related sales invoices.
 ON UPDATE CASCADE: If ID_Product is updated, the related sales invoices will be
automatically updated.

1.6 Normalize the database to eliminate duplicate data and ensure data consistency.
1.6.1 Steps for Normalization:
 First Normal Form (1NF):
 Ensure that each column contains only atomic (indivisible) values.
 Ensure that there are no repeating groups of data.
 Second Normal Form (2NF):
 Eliminate partial dependencies by ensuring that all non-key attributes are fully functionally
dependent on the primary key.
 This applies to tables with composite primary keys.
 Third Normal Form (3NF):
 Remove transitive dependencies, ensuring that non-key attributes are only dependent on the
primary key.
1.6.2 Revised Schema (Normalized)
 Table: Supplier
 Attributes:
o ID_Supplier (Primary Key)
o Name_Supplier
o Address
o Phone
o No changes needed; this table is already normalized.
 Table: Product
 Attributes:
o ID_Product (Primary Key)
o Name_Product
o ID_Supplier (Foreign Key)
o Price
o Remove Quantity from this table, as it is a transactional attribute (specific to invoices).
 Table: Staff
 Attributes:
o ID_Staff (Primary Key)
o Name_Staff
o Sex
o Address
o Phone
o No changes needed; this table is already normalized.
 Table: Customers
 Attributes:
o ID_Customer (Primary Key)
o Name_Customer
o Sex
o Address
o Phone
o No changes needed; this table is already normalized.
 Table: Import_Invoice
 Attributes:
o ID_Invoice (Primary Key)
o Date_of_Import
o ID_Staff (Foreign Key)
o ID_Supplier (Foreign Key)
o Remove ID_Product, Quantity, Unit_Price, and Total_Money as they belong to a line-item
table.
 Table: Import_Invoice_Line
 Attributes:
o ID_Invoice (Composite Primary Key, Foreign Key to Import_Invoice)
o ID_Product (Composite Primary Key, Foreign Key to Product)
o Quantity
 o Unit_Price
o Total_Money (can be derived as Quantity * Unit_Price, optionally stored for performance)
 Table: Sales_Invoice
 Attributes:
o ID_Sales_Invoice (Primary Key)
o Date_of_Sale
o ID_Staff (Foreign Key)
o ID_Customer (Foreign Key)
o Remove ID_Product, Quantity, Unit_Price, and Total_Money as they belong to a line-item
table.
 Table: Sales_Invoice_Line
 Attributes:
o ID_Sales_Invoice (Composite Primary Key, Foreign Key to Sales_Invoice)
o ID_Product (Composite Primary Key, Foreign Key to Product)
o Quantity
o Unit_Price
o Total_Money (can be derived as Quantity * Unit_Price, optionally stored for performance)

1.7 Design the table about user requirements and system requirements for the database

Requirement Description
Type

General Build software to support Store X in effectively managing operations, including sales,
Requirements inventory, and employee management.

Software Develop using .Net Framework 4.5 (C#) or later versions, with SQL Server 2012 or
Platform higher for data storage.

Security Implement robust security measures, including encrypted passwords, role-based

access control, and regular updates for security patches.

Product Enable comprehensive product catalog management, including product code, name,
Management price, inventory, and images. Support functionality for adding, editing, deleting,
searching, and filtering products. Update inventory during import/export
processes.
 Employee Manage employee details, including employee code, name, position, and roles.
Management Provide functionalities for adding, editing, deleting, and searching employees.
Require password updates upon first login and enforce role-based access rights.

Customer Maintain customer data, including code, name, phone number, and address.
Management Enable functionalities for adding, editing, deleting, and searching customers.
Store purchase history for each customer.

Statistics Generate statistics, including product import/export data, daily/monthly/yearly

revenue, and profit margins by product or employee.

Access Rights Define access levels: Admins have full access to all functions; sales staff are
restricted to sales-related functions; warehouse staff are limited to inventory-
related tasks. Employees cannot add/delete staff or access statistics unless
authorized.

Security Use strong encryption for data, securely manage sensitive information, and
Enhancements conduct regular updates to ensure compliance with the latest security standards.

CHAP II : Develop a fully-functional relational database

system, based on an existing system design (LO2)
1. Develop the database system with evidence of user interface, output and
data validations, and querying across multiple tables (P2)
1.1 Creating Tables, Relationships, and Constraints:
 After the user interface is set up, we will begin coding the database to provide an overview of
our student management system.
 The structure of these databases will be based on the tables, primary keys, and secondary keys
that were developed in assignment 1.
 Initially, we will create the database using the keyword provided below, and then activate the
database system we just created for use.
 Figure 13 : Create Database
 Next, we will create tables in turn to have a complete database to proceed with adding data to
the system
 PRODUCT

Figure 14 : Product
 CUSTOMER :

Figure 15 : Customer

 STAFF

Figure 16 :Staff
 Supplier
 Figure 17 : Supplier

 Import_Invoice

Figure 18 : Import_Invoice
 Sales_Invoice

Figure 19 : Sales_Invoice

 After coding and executing the commands, this is the result we obtain.
 Upon creation, the Microsoft SQL Server Management system has successfully generated
tables, views, security configurations, and full storage, thereby completing the system.
 Here are the results after we have created the tables.

 Querying across multiple tables: We have the affiliations and relationships of the copies with
each other after constructing the appropriate components in the database
1.2 Creating Relationships
 Supplier → Product: 1-N Relationship
 Supplier can supply many Products.
 A Product is linked to a Supplier via ID_Supplier.

 Staff → Import_Invoice: 1-N Relationship

  Staff can create multiple Import_Invoice records.
 An Import_Invoice is created by a Staff member via ID_Staff.

 Supplier → Import_Invoice: 1-N Relationship

 Supplier can have many Import_Invoice records associated with it.
 An Import_Invoice references a Supplier via ID_Supplier.

 Product → Import_Invoice_Line: 1-N Relationship

 A Product can appear in multiple Import_Invoice_Line records.
 Each Import_Invoice_Line references a Product via ID_Product.

 Import_Invoice → Import_Invoice_Line: 1-N Relationship

 An Import_Invoice can have many associated Import_Invoice_Line records.
 Each Import_Invoice_Line is linked to an Import_Invoice via ID_Invoice.
  Staff → Sales_Invoice: 1-N Relationship
 Staff can create multiple Sales_Invoice records.
 Each Sales_Invoice is associated with a Staff member via ID_Staff.

 Customer → Sales_Invoice: 1-N Relationship

 A Customer can have many Sales_Invoice records.
 Each Sales_Invoice is linked to a Customer via ID_Customer.

 Product → Sales_Invoice_Line: 1-N Relationship

 A Product can appear in multiple Sales_Invoice_Line records.
 Each Sales_Invoice_Line references a Product via ID_Product.

1.3. Query to INSERT data with illustration of final result

 Insert Data into Supplier

 Insert Data into Product

  Insert Data into Staff

 Insert Data into Customer

 Insert Data into Sales_Invoice

 Insert Data into Import_Invoice

1.4 The SQL script you provided is used to add foreign key constraints to the database.
These constraints ensure that data between related tables is consistent and does not lose
integrity.
 Data Integrity:
 Foreign key constraints enforce relationships between tables and ensure that data between
them remains consistent. For example:
 In the Sales_Invoice table, the ID_Staff column must refer to a valid ID_Staff from the Staff
table. If the referenced employee is deleted, the ON DELETE CASCADE action ensures that
all related sales invoices are also deleted, preventing orphan records.
 If the ID_Product in the Sales_Invoice_Line table does not exist in the Product table, an error
occurs, preventing invalid data from being entered into the database.
 Consistency:
 Referential integrity: Foreign key constraints ensure that each record in the child table (e.g.
Sales_Invoice_Line, Import_Invoice_Line) always refers to a valid record in the parent table
(e.g. Product, Import_Invoice).
 Cascading Update/Delete: The ON DELETE CASCADE and ON UPDATE CASCADE
options ensure that when a record in the parent table is modified (e.g. a Product record) or
deleted, related records in the child tables are automatically updated or deleted, preventing
inconsistencies.
 Preventing Anomalies:
 Foreign Key Constraints prevent:
 Orphan Records: A record in a child table (e.g. a sales transaction in Sales_Invoice) will not be
suspended if the corresponding record in the parent table (e.g. the related Employee or
Customer) is deleted.
 Invalid Data: Ensures that you cannot enter a Sales_Invoice for a non-existent Product or
Employee member, applying valid references.
 Example of Cascading Actions:
1.5 Develop a user interface (UI) for users to interact with the database (e.g.,
forms, menus).
 Product Management Form:
 Functions: Add new, Fix, delete, Back

 And there is a separate product search form.

 Staff Management Form:
 Functions: Add new, Fix, delete, Back
 And there is a separate Staff search form.
 Login and Account Management Form:
 Function: Login with username and password, change password on first login and Remember
password .

 When you log in to your account, you will go to the App's home page:

 Home:
 o Functions: Information Statistical, Search, Come back and Exit

 In Information Statistical

o Customer
 o Staff

 Product:

o Sales_Invoice
2. Implement a query language into the relational database system (P3)
2.1 Assess the suitability of the T-SQL query language for sales software applications.
 T-SQL (Transact-SQL) is an extension of the Structured Query Language (SQL) developed by
Sybase and Microsoft, offering additional features such as transaction control, error handling,
row processing, and the use of declared variables.
 All applications interacting with SQL Server communicate by sending T-SQL statements to the
server. T-SQL queries typically include commands such as the SELECT statement, selecting
specific columns, labeling output columns, filtering rows, and modifying search conditions.
 T-SQL identifiers are used for all databases, servers, and database objects within SQL Server.
These identifiers encompass tables, constraints, stored procedures, views, columns, and data
types. Each identifier must have a unique name, is assigned upon the creation of an object, and
serves to identify that object.
 Why T-SQL is suitable for the above sales application (scenario)?
 Relational Database Management System (RDBMS) Integration
o Sales applications typically require a relational database to handle structured data
efficiently. T-SQL is specifically built for relational databases like Microsoft SQL Server,
which is designed to manage structured data across multiple related tables.
o The sales application involves multiple related entities (e.g., customers, products, sales
invoices, staff, suppliers), and T-SQL can easily manage the relationships between these
tables using foreign keys and join operations.
 Data Integrity and Consistency
o T-SQL supports constraints like primary keys, foreign keys, and unique constraints, which
are essential for ensuring referential integrity in a sales application.
o The schema for the sales application uses foreign key constraints (as demonstrated earlier) to
ensure that related records (e.g., sales invoices, customer data) are consistent. This helps
 prevent orphaned data or invalid references (such as a sale being associated with a non-
existent product or customer).
 Security Features
o Sales applications often require strict control over who can access and modify data. T-SQL
offers role-based security, which allows you to control user access and permissions based on
roles (e.g., sales staff, inventory manager).
o Using T-SQL security features, the application can ensure that only authorized personnel can
view sensitive customer data or modify inventory records.

2.2 Implement data connection and execute queries to fulfill software functionalities.

 Connection String is a text-based configuration used by applications to establish a connection to

a database. This string typically includes crucial information such as the server name, database
name, login credentials, and other configuration parameters required for authentication and
connection setup.Common Properties in a Connection String
 Server: Specifies the address of the SQL server. This can be an IP address, hostname, or fully
qualified domain name.
 Database: Defines the name of the target database to connect to.
 User Id and Password: Provides login credentials required for SQL Server authentication.
 Integrated Security: Indicates whether Windows authentication is used (True - Yes, False - No).
 Connection Timeout: Sets the maximum time (in seconds) to wait for establishing a connection.
 Encrypt: Enables encryption for the connection, ensuring data security.
 TrustServerCertificate: Allows connections with unauthenticated certificates. Note: This
should only be used in testing environments
 CONCLUSION
 During the development and deployment of the sales management system for Store X, we
applied relational database design principles to ensure the system's efficiency and
completeness. The system was structured with at least four interconnected tables to fulfill user
and system requirements, covering product, employee, customer, and invoice management.
 Database Design: Entity-Relationship Diagrams (ERD) were used to define and visualize
relationships between core entities.
 System Construction: The system was built with demonstrated user interfaces, data validation
mechanisms, and SQL queries operating across multiple tables.
 Testing and Validation: Rigorous testing ensured the system met all functional requirements,
including performance, security, and scalability.
 Documentation and Support: Comprehensive technical documentation and user manuals were
prepared to facilitate system usage, implementation, and long-term maintenance..
 REFERENCES
 https://thinhnotes.com/chuyen-nghe-ba/erd-la-gi/