Final Documentation for All Migration/RDS Scripts

[tanishapatil1234]

Database Migration Scripts Documentation

Overview

This documentation provides details on the two primary scripts used for migrating the RDS database: db_init.py and db_migrate.py. These scripts are designed to initialize the database schema and migrate data from an old database to a new one.

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db_init.py

Description

The db_init.py script is responsible for initializing the database schema. It performs the following steps:

1. Warning the User: Alerts the user about potential data loss.
2. Database Backup: Backs up the current database to a specified location.
3. Schema Initialization: Drops any existing tables and creates new ones based on the defined schema.
4. Data Loading: Adds default test data to the newly created tables.

Usage

Run the script from the terminal :

cd scripts; ./db_init.py

Functions

• backup_database(db_uri, backup_uri)
  • Backs up the current database to the specified backup location.
  • Supports SQLite and other production databases
• main()
  - Main function that coordinates the schema initialization process.
  - Drops existing tables, creates new ones, and loads test data.

Important Notes

• The script will drop all existing tables, resulting in data loss. Ensure you have backups before running this script.

db_migrate.py

Description

The db_migrate.py script is responsible for migrating data from an old database to a new one. It follows these steps:

1. Warning the User: Alerts the user about potential data loss.
2. Database Backup: Backs up the current database to a specified location.
3. Schema Initialization: Drops existing tables and creates new ones based on the defined schema.
4. Data Migration: Authenticates with the old database, extracts data, and loads it into the new database.

Usage

Run the script from the terminal :

cd scripts; ./db_migrate.py

Functions

backup_database(db_uri, backup_uri, db_string)

• Backs up the current database to the specified location.
• Supports both MySQL and SQLite databases.

create_database(engine, db_name)

• Creates the database if it does not exist.
  authenticate(uid, password)
• Authenticates with the old database and returns an authentication token.

extract_data(cookies)

• Extracts data from the old database using the provided authentication token.

write_data_to_json(data, json_file)

• Writes extracted data to a JSON file, with a backup if the file already exists.

read_data_from_json(json_file)

• Reads data from a JSON file.

main()

• Main function that coordinates the entire migration process.
• Authenticates with the old database, extracts data, and loads it into the new database.

Important Notes

• The script provides fallback mechanisms. If authentication with the old database fails, it uses a local JSON file to load data.
• The script supports MySQL and SQLite for database backup and restoration.