BankDB — Database System for a Banking Application

BankDB is a relational database designed to support the core operations of a modern bank.
It manages customers, accounts (checking & savings), cards, loans, transactions, employees, and bank branches.
The system enables efficient data storage, retrieval, updates, integrity constraints, and relational querying.

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Features

• Customer, account, loan, card & transaction management
• Many-to-many relationships (customers ↔ accounts, accounts ↔ cards)
• Branch & employee hierarchy
• Useful SQL views (customer account summary, employee branch summary)
• ER model & relational schema included

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Tech Stack

• SQL-based relational DBMS (MySQL)
• Normalized database schema with constraints
• ER & relational diagrams
• Backend: Python (Flask)
• Frontend: Bootstrap 5, Jinja2

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Bank Management Web Application

User Manual & Technical Guide

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1. Project Overview

This is a full-stack web application developed using Python (Flask) and MySQL.
It provides a secure interface for customers to:

• View bank accounts
• Perform money transfers
• Pay loans and credit cards
• Manage personal details
• Locate bank branches

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2. Prerequisites

Before running the application, ensure you have the following installed:

• Python 3.x
• MySQL Server (must be running properly)
• Python libraries:
  • flask
  • mysql-connector-python

Install Dependencies

pip install flask mysql-connector-python

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3. Database Setup (CRITICAL STEP)

The application relies on a MySQL database named BankDB.
You must set this up manually because the provided SQL dump file may not create the database automatically.

Setup Steps

1. Open your terminal / command prompt
2. Log in to MySQL:

   mysql -u root -p

3. Create the database:

   CREATE DATABASE IF NOT EXISTS BankDB;
   EXIT;

4. Import the SQL dump (from the project directory):

   mysql -u root -p BankDB < Dump20251219.sql

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4. Configuration

The application connects to the database using credentials defined in app.py.

Locate the db_config dictionary (approximately line 11):

db_config = {
    'host': 'localhost',
    'user': 'root',
    'password': 'YOUR_MYSQL_PASSWORD',
    'database': 'BankDB'
}

Important:
The current code uses password 1234.
Change this to match your local MySQL root password.

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5. How to Launch the Application

1. Navigate to the project directory:

   cd path/to/project_folder

2. Run the Flask application:

   Windows (recommended):

   python app.py

   Linux / macOS:

   python3 app.py

3. If successful, you will see:

   Running on http://127.0.0.1:5000
   

4. Open your web browser and go to:

   http://127.0.0.1:5000
   

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6. How to Use the Application

A. Login

• No separate users table is used
• Authentication is performed using Customer TIN
• Any password is accepted

Example valid TIN:

123456789
(User: Maria Papadopoulou)

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B. Dashboard

After login, the dashboard displays:

• All customer accounts
• Account Number
• Currency
• Status
• Current Balance

Notes:

• Balances are calculated dynamically using the accounts_balance SQL view
• Total Net Worth includes balances from all accounts, active or inactive

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C. Money Transfer

1. Click Transfer
2. Select the source account
3. Enter the destination account number
   Example:

   GR1311891434567890123456789
   

4. Enter a positive amount
5. Click Confirm Transfer

Validation Includes:

• Sufficient funds
• Valid destination account

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D. Branch Locator

• Click Branches
• View all bank branches with:
  • Address
  • Operating hours
  • Contact details

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E. Pay Loan

• View active loan details:
  • Loan amount
  • Expiration date
  • Current debt
• Select an account to pay from
• Enter payment amount
• System prevents overpayment and insufficient balance

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F. Pay Credit Card

• Displays credit cards with outstanding debt
• Select:
  • Credit card
  • Source account
• Enter payment amount
• Credit card available balance is updated accordingly

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G. Settings

From the Settings page, users can:

• View personal details (Name, TIN, phone numbers)
• Update physical address
• Manage email addresses:
  • Add
  • Update
  • Delete

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7. Technical Implementation Details

Frameworks

• Backend: Python Flask
• Frontend: Bootstrap 5, Jinja2
• Database: MySQL

Security

• Prepared statements for all queries (SQL Injection protection)
• Flask session management for authentication

Transactions & Consistency

• ACID-compliant database transactions:
  • conn.start_transaction()
  • commit()
  • rollback()
• Guarantees no partial or lost money transfers

Application Logic

• Transaction IDs generated manually (MAX(TransactionID) + 1)
• Extensive use of SQL Views:
  • customer_accounts
  • accounts_balance
  • Summary and reporting views

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8. Notes

• MySQL server must be running before starting the app
• Database must be created before importing the dump
• Always verify database credentials
• Intended for academic and educational use

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End of README