postgres

PostgreSQL Storage Example

This example demonstrates how to use the @loro-extended/adapter-postgres storage adapter with @loro-extended/repo.

Prerequisites

• Docker and Docker Compose (for running PostgreSQL)
• Node.js 18+
• pnpm

Setup

1. Start PostgreSQL:

pnpm db:up

This starts a PostgreSQL container with:

• User: loro
• Password: loro
• Database: loro_example
• Port: 5432

2. Install dependencies:

pnpm install

3. Run the example:

pnpm start

What the Example Does

1. Creates a PostgreSQL connection pool
2. Creates a PostgresStorageAdapter with the pool
3. Creates a Repo with the storage adapter
4. Creates a document and makes changes
5. Queries the database directly to show stored chunks
6. Makes additional changes and shows how chunks accumulate

Expected Output

🐘 PostgreSQL Storage Adapter Example

📦 Creating storage adapter...
🔧 Creating repo with storage...

📝 Creating document...
✅ Document created: my-doc
📄 Content: {
  "root": {
    "message": "Hello from PostgreSQL!",
    "timestamp": 1234567890123
  }
}

⏳ Waiting for storage to persist...

🔍 Querying database directly...
📊 Stored chunks:
   - my-doc::update::1234567890123-0000: 42 bytes

📝 Making another change...
📄 Updated content: {
  "root": {
    "message": "Hello from PostgreSQL!",
    "timestamp": 1234567890123,
    "updated": true,
    "updateTime": 1234567890456
  }
}

🔍 Querying database again...
📊 All stored chunks:
   - my-doc::update::1234567890123-0000: 42 bytes
   - my-doc::update::1234567890456-0000: 28 bytes

🧹 Cleaning up...
✅ Done!

Cleanup

To stop and remove the PostgreSQL container:

pnpm db:down

To also remove the data volume:

docker-compose down -v