Object relational mapping

lastmod 2025-03-17created 2014-02-2410 edits

To put ORM simply, it is something like setting up mappings between objects and relations? If "object" here means the object of what we commonly call OOP (Object-Oriented Programming), what does "relation" mean? It is very basic, but it refers to the relational databases that we (developers) commonly use.

What is an Object Relational Mapper?

• Responsible for synchronizing database entities (a kind of table row) with Java objects
• Hibernate is a framework that plays this role
• All SQL statements are generated and executed by the framework
• When SQL work is needed, it is done through HSQL (similar to EJB-QL)
• HSQL is an object-oriented query language processed in front of the actual SQL

Projects

• TopLink
• Cocobase
• JDO implementations

Java

• Hibernate

JavaScript/TypeScript

• Prisma
• Drizzle
• Sequelize
• TypeORM
  • Safe-TypeORM - A TypeORM helper library with automatic autocompletion, error checking, and performance tuning
• Kysely

Python

• SQLAlchemy

Android ORM Library

• Hello world: ORM on Android ¹

Favorite site

• Wikipedia (en) Explanation of ORM
• Wikipedia (en) List of object-relational mapping software
• What is ORM?

References