Syntax AI MySQL setup

This SQL matches the current project behavior in frontend/src/server.js.
It creates the database and the single table used by the app.

1. Open MySQL
mysql -u root -p

2. Create the database
CREATE DATABASE IF NOT EXISTS react_mysql_db;

3. Use the database
USE react_mysql_db;

4. Create the table used by signup, login, and option storage
CREATE TABLE IF NOT EXISTS user_data (
    id INT AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(100) NOT NULL,
    password VARCHAR(255) NOT NULL,
    user_option VARCHAR(100) DEFAULT NULL,
    generate_code_prompt TEXT DEFAULT NULL,
    generate_code_language VARCHAR(100) DEFAULT NULL,
    modify_code_input LONGTEXT DEFAULT NULL,
    modify_code_logic LONGTEXT DEFAULT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

5. Add an index to speed up login lookups
CREATE INDEX idx_user_login ON user_data (username, password);

6. Optional: prevent duplicate usernames on signup
ALTER TABLE user_data
ADD CONSTRAINT uq_user_data_username UNIQUE (username);

7. Verify the table structure
DESCRIBE user_data;

8. Optional test insert for a signup-style row
INSERT INTO user_data (username, password)
VALUES ('testuser', 'testpass');

9. Optional test insert for a Generate Code action row
INSERT INTO user_data (
    username,
    password,
    user_option,
    generate_code_prompt,
    generate_code_language,
    modify_code_input,
    modify_code_logic
) VALUES (
    'testuser',
    'testpass',
    'Generate Code',
    'Write a Python function to reverse a string',
    'Python',
    NULL,
    NULL
);

10. Optional test insert for a Modify Code action row
INSERT INTO user_data (
    username,
    password,
    user_option,
    generate_code_prompt,
    generate_code_language,
    modify_code_input,
    modify_code_logic
) VALUES (
    'testuser',
    'testpass',
    'Modify Code',
    NULL,
    NULL,
    'for(i=0;i<n;i++){sum+=i;}',
    'Optimize and modernize this code'
);

11. Verify inserted rows
SELECT * FROM user_data;

12. Finish
EXIT;

Notes
- The app currently stores plain-text passwords. That is how the existing code works, but it is not safe for production.
- The app inserts new rows for user actions instead of updating one user profile row.
- The login query used by the app is:
  SELECT * FROM user_data WHERE username = ? AND password = ?;
- The project expects these env values:
  DB_HOST=localhost
  DB_USER=root
  DB_PASSWORD=your_mysql_password_here
  DB_NAME=react_mysql_db