What is Sequelize? Sequelize is a powerful library in Javascript that makes it easy to manage a SQL database. ... At its core, Sequelize is an Object-Relational Mapper – meaning that it maps an object syntax onto our database schemas. Sequelize uses Node. JS and Javascript's object syntax to accomplish its mapping. What is Sequelize in node JS? Sequelize is a promise-based ORM for Node. js and io. js. It supports the dialects PostgreSQL, MySQL, MariaDB, SQLite and MSSQL and features solid transaction support, relations, read replication and more. Does MongoDB support Sequelize? Lyft, MIT, and Bodybuilding.com are some of the popular companies that use MongoDB, whereas Sequelize is used by WebbyLab, Hostr, and Decision6. Is Sequelize a framework? Sequelize and Entity Framework can be categorized as "Object Relational Mapper (ORM)" tools. Sequelize and Entity Framework are both open source tools. What are the advantages of Sequelize? Sequelize. js is an ORM (Object/Relational Mapper) which provides easy access to MySQL, MariaDB, SQLite or PostgreSQL databases by mapping database entries to objects and vice versa. It has very powerful migrations mechanism that can transform existing database schema into a new version. Why should I use an ORM? The most important reason to use an ORM is so that you can have a rich, object oriented business model and still be able to store it and write effective queries quickly against a relational database. ... A simple ORM query might select all shapes in your database. You get a collection of shapes back. What the heck is a Sequelize model? A model is an abstraction that represents a table in your database. In Sequelize, it is a class that extends Model. The model tells Sequelize several things about the entity it represents, such as the name of the table in the database and which columns it has (and their data types). A model in Sequelize has a name.