DB Migrate
A lightweight Node.js toolkit for migrating schemas and data across MongoDB, MySQL, and PostgreSQL without introducing an ORM.
Current portfolio record
Verified against the public repository and current documentation
Purpose and use case
Why this project was built
Built for developers who need to move application data between common databases, create portable backups, or test a database transition without adopting a larger ORM or migration framework.
Overview
What the project is
DB Migrate is a dependency-light command-line utility focused on practical database portability. It uses a small adapter contract and a canonical schema representation so the same migration, export, import, validation, and diff workflows can work across document and relational databases.
Problem
What it is designed to solve
Database migration tools are often tied to one database, one ORM, or one schema format. Cross-database moves also introduce type differences, large datasets, partial failures, and destructive operations that require explicit handling.
Approach
How the project addresses it
The toolkit separates database-specific adapters from schema comparison and data transfer. It reads and writes in bounded batches, records resumable checkpoints, preserves supported value types in NDJSON exports, and reports unsupported database behavior instead of hiding it.
Key features
- MongoDB, MySQL, and PostgreSQL adapters behind one focused interface
- Direct database-to-database schema and data migration
- Portable NDJSON export and import with typed value markers
- Schema inspection, conservative type mapping, and schema diff
- Batched transfer with checkpoints for resumable migrations
- Filters, entity renaming, JavaScript transforms, dry runs, seeding, and guarded rollback
Architecture highlights
- A canonical schema keeps database metadata independent from individual drivers
- Native database drivers avoid an unnecessary model or ORM layer
- Keyset pagination is used when a stable identity is available, with documented fallbacks
- Rollback is intentionally limited to entities created by the latest migration
Engineering challenges
- Mapping document fields and nested values into relational column types without destructive assumptions
- Keeping large migrations resumable and memory-bounded across databases with different pagination behavior
- Representing indexes, keys, and unsupported database features honestly across different engines
Implemented outcomes
- Expanded the original MongoDB script into a consistent three-database migration toolkit
- Added unit and optional integration testing for adapters, schema mapping, and transfer behavior
- Published clear CLI, configuration, architecture, type-mapping, troubleshooting, and contribution documentation