Lesson 3: Running the Application and Database Setup

Running Your Flask Application

Starting the Application:

• Open PowerShell or terminal in your project directory
• Ensure your virtual environment is activated (you should see "(venv)")
• Run the command: python app.py
• Navigate to http://127.0.0.1:5000 in your browser

Expected Initial Behavior:

• Application should load and display the starter template
• When you click "Examples", you should get an error: "The table does not exist"
• This error is expected - it means the database schema hasn't been set up yet

Troubleshooting Phantom Processes

What is a Phantom Process?

• Sometimes applications keep running in the background after closing Cursor
• When you run python app.py, it may show content that doesn't match your current code
• This means an old version is still running on port 5000

Using Claude AI to Kill Phantom Processes:

• Open Claude in Cursor
• Type: "kill the processes running on 127.0.0.1:5000"
• Claude will search for and terminate background processes
• It may take several attempts - Claude will try different methods
• Once successful, you can run your application normally

Database Schema Setup with Claude AI

Using Claude to Deploy Your Database Schema:

• Identify the schema.sql file in your project (contains CREATE TABLE statements)
• Tell Claude: "Using the database connection in the .env file, send up the schema.sql to the MySQL database"
• Add: "and seed the table using the seed data"
• Claude will automate the entire database setup process

What Claude Will Do:

• Try to connect directly via command line first
• If that fails, install MySQL connector for Python
• Create a Python script to handle the database connection
• Execute the schema.sql file to create tables
• Run seed data to populate tables with initial records
• Handle any errors automatically and try alternative methods

Alternative Manual Method:

• Copy the contents of schema.sql
• Open MySQL Workbench and paste into query window
• Click the lightning bolt to execute the queries
• This creates the tables directly in MySQL Workbench

Verifying Your Starter Kit

Testing Application Functionality:

• After database setup, refresh your browser
• Click on "Examples" (or whatever your template uses)
• You should now see the table with data instead of an error
• This confirms your database connection and schema are working

Starter Kit Features to Test:

• Modal for Adding: Working modal dialog for creating new records
• Edit Functionality: Pre-loads existing data for editing
• Delete Confirmation: Modal confirmation before deletion
• Data Display: Proper table rendering with all records

Lesson 3 Goals:

• Preload your database with schema and seed data
• Check that your application actually works
• Confirm all starter kit features are functional