data_migration.md

Data Migration: Supabase to Data Connect

Migrating data involves exporting rows from Supabase (PostgreSQL) and importing them into your new Data Connect (Cloud SQL) database.

Method 1: The "Pure SQL" approach (Recommended for Bulk)

Since both are PostgreSQL, you can use standard tools.

1. Export from Supabase

Use pg_dump to export your data (data only, no schema, as Data Connect manages schema).

# Get connection string from Supabase settings
pg_dump "postgresql://postgres:PASSWORD@db.PROJECT.supabase.co:5432/postgres" \
  --data-only \
  --table=<my_table> \
  --column-inserts \
  > supabase_data.sql

2. Import to Cloud SQL

Connect to your Data Connect Cloud SQL instance and restore. Note: You may need to create a Bastion host or use the Cloud SQL Auth Proxy to connect inside a VPC.

psql "postgresql://user:pass@localhost:5432/dataconnect" -f supabase_data.sql

Warning

Schema Mismatch Risk: Data Connect generates table names and column names based on your GraphQL schema. They might NOT match Supabase exactly (e.g., camelCase vs snake_case). Solution: Inspect the generated Cloud SQL schema first, then edit your .sql dump to match the table/column names.

Method 2: Scripted GraphQL Mutations (Recommended for Safety)

This method ensures your data adheres to your new Data Connect schema validation and handles Foreign Keys correctly.

1. Export Data to JSON

Export your Supabase data to JSON files.

Export Business Data:

node SQLMigration/data/export_supabase_data.js

Export Users (Reuse Auth Export):

node SQLMigration/auth/export_supabase_auth.js

2. Import using Data Connect Admin SDK

We use the Data Connect Admin SDK to bypass Client Auth for migration scripts.

Step 2.1: Import Users to Cloud SQL Since your tables likely reference users by Foreign Key, users must exist in the SQL User table first.

node SQLMigration/data/import_users_data.js

Step 2.2: Import Business Data Then import your data tables, linking them to the correct user.

node SQLMigration/data/import_firebase_data.js

Sample Script (import_firebase_data.js)

const { importMyTable, connectorConfig } = require('../../src/dataconnect-admin-generated');
const { getDataConnect } = require('firebase-admin/data-connect');

// Initialize Admin SDK with Service Account...
const dataConnect = getDataConnect(connectorConfig);

async function runImport() {
  const items = require('./supabase_data.json');
  for (const item of items) {
    // Map fields from JSON to Mutation Arguments
    await importMyTable(dataConnect, {
      id: item.id,
      title: item.title,
      // ... match your schema
    });
  }
}