Sequelize

Promise-based Node.js ORM that abstracts SQL across PostgreSQL, MySQL, MariaDB, SQLite, Microsoft SQL Server, Snowflake, Oracle DB, and DB2. Lets developers define models, associations, and queries in JavaScript or TypeScript while keeping full control over database interactions.

One of the most widely adopted ORMs in the Node.js ecosystem, with a decade-long track record. Sequelize distinguishes itself from alternatives like Prisma and TypeORM with broad multi-database support including Oracle and DB2, and a model-centric API suited to teams migrating from classic ORM patterns in other languages.

Key capabilities:

• Model definitions with associations, hooks, and optional automatic table synchronization
• Transactions, migrations, and soft deletion with paranoid mode
• JSON and JSONB querying on supported databases
• TypeScript support with strong typing for models and queries
• Connection pooling and read replicas for production workloads

Sequelize suits backend APIs, full-stack Node applications, and services that need to support multiple SQL databases from a single codebase. Teams use it for Express, Fastify, or NestJS backends where relational modeling and migrations matter. The mature ecosystem integrates with common tooling such as Sequelize CLI for migrations and existing testing frameworks.