Push Notification Service - Database Seeder

This package provides tools to generate realistic sample data for the Push Notification Service database. It supports multiple approaches including direct ORM-based generation, SQL file generation, and Docker-based setup.

Overview

The database seeder creates the following sample data:

• Users: People who receive notifications
• Devices: Mobile, web, or other devices registered to users
• Notifications: Messages sent to users
• User Preferences: User-specific notification preferences
• Sent Notifications: Records of notifications that have been delivered
• Notification Logs: Detailed tracking of notification lifecycle

Prerequisites

• Node.js 14+ and npm
• PostgreSQL 12+ (if using direct database insertion)
• Docker and Docker Compose (if using the Docker approach)

Installation

Option 1: Automated Setup

Run the installation script:

chmod +x setup-seed-tools.sh
./setup-seed-tools.sh

Option 2: Manual Setup

1. Install dependencies:

npm install sequelize pg pg-hstore faker uuid dotenv

2. Create a .env file with your database configuration:

DB_HOST=localhost
DB_PORT=5432
DB_NAME=notification_db
DB_USER=admin
DB_PASSWORD=admin123

# Data generation options
USER_COUNT=100
NOTIFICATION_COUNT=500
START_DATE=2023-01-01
TRUNCATE_FIRST=true

# Mode: 'sequelize' or 'sql'
MODE=sequelize
EXECUTE_SQL=false

Usage

Basic Usage

To generate data using the Sequelize ORM (directly inserts into database):

node data-generator.js

Advanced Usage

The enhanced data generator supports multiple modes and options:

Generate with Sequelize ORM

MODE=sequelize node enhanced-data-generator.js

Generate SQL File Only

MODE=sql EXECUTE_SQL=false node enhanced-data-generator.js

Generated SQL will be saved to ./generated-data/seed-data.sql.

Generate and Execute SQL

MODE=sql EXECUTE_SQL=true node enhanced-data-generator.js

Customize Data Volume

USER_COUNT=500 NOTIFICATION_COUNT=2000 node enhanced-data-generator.js

Docker-based Approach

Using Docker eliminates the need to install Node.js and dependencies locally:

1. Ensure Docker and Docker Compose are installed
2. Create necessary files (data-generator.js, docker-compose.yml)
3. Run:

docker-compose up

This will:

• Start a PostgreSQL container
• Initialize the database schema
• Run the data generator script

Make Commands

If you've set up the Makefile, you can use these simplified commands:

# Install dependencies
make install

# Generate data using Sequelize ORM
make seed

# Generate SQL file only
make sql

# Generate and execute SQL
make execute-sql

# Run using Docker
make docker-seed

# Clean generated files
make clean

# Reset the database (drop and recreate)
make reset-db

Configuration

The following environment variables can be set:

Variable	Description	Default
MODE	Generation mode: 'sequelize' or 'sql'	'sequelize'
USER_COUNT	Number of users to generate	100
NOTIFICATION_COUNT	Number of notifications to generate	500
START_DATE	Start date for random dates	'2023-01-01'
TRUNCATE_FIRST	Whether to truncate tables before inserting	false
EXECUTE_SQL	Execute generated SQL file	false
OUTPUT_DIR	Directory for SQL output files	'./generated-data'
DB_HOST	Database host	'localhost'
DB_PORT	Database port	5432
DB_NAME	Database name	'notification_db'
DB_USER	Database user	'admin'
DB_PASSWORD	Database password	'admin123'

Generated Data

The data generator creates:

• 100 users (configurable)
• 1-3 devices per user
• 500 notifications (configurable)
• 1-4 notification preferences per user
• ~80% of notifications marked as sent
• 2-5 log entries per notification

Types of data included:

• Device types: android, iOS, web
• Notification types: message, friend_request, payment, security, marketing, system
• Log types: created, processed, sent, delivered, failed, clicked

Data Model

Troubleshooting

Database Connection Issues

If you encounter connection errors:

1. Verify your database credentials in .env
2. Ensure PostgreSQL is running
3. Check if the database exists and is accessible

Example troubleshooting:

# Check PostgreSQL status
sudo service postgresql status

# Connect to database manually
psql -h localhost -U admin -d notification_db

# Check if tables exist
\dt

Duplicate Key Errors

If you run the script multiple times, you may get unique constraint violations:

• Set TRUNCATE_FIRST=true to clear tables before inserting
• Or run make reset-db to completely reset the database

Performance Issues

For large volumes of data:

• Use the SQL generation mode (MODE=sql) which is more efficient
• Increase Node.js memory if needed: NODE_OPTIONS=--max-old-space-size=4096