What is ORM?
Object-Relational Mapping (ORM) is a programming technique that maps object-oriented programming models to relational databases. It provides a bridge between object-oriented programming languages and relational databases, allowing developers to work with objects instead of tables.
How does ORM work?
ORM creates a mapping between objects in an object-oriented programming language and tables in a relational database. The properties of an object are mapped to columns in a table, and the relationships between objects are mapped to relationships between tables. ORM tools automatically generate SQL queries based on the mapping between objects and tables.
ORM has several benefits, including:
- Reduced code complexity: ORM eliminates the need for developers to write complex SQL queries, reducing the amount of code required to perform database operations.
- Improved maintainability: Since ORM uses an abstraction layer between the application and the database, changes to the database schema can be made without requiring changes to the application code.
- Increased productivity: By reducing the amount of code required to interact with the database, developers can focus on other aspects of the application and be more productive.
Types of ORM in Various Programming Languages
Hibernate (Java)
Hibernate is a popular ORM tool for Java programming language. It supports multiple databases such as MySQL, Oracle, and SQL Server.
Other examples:
- EclipseLink
- MyBatis
- Spring Data JPA
- JOOQ
SQLAlchemy (Python)
SQLAlchemy is a popular ORM tool for Python programming language. It provides a set of high-level APIs for working with databases and supports multiple databases such as PostgreSQL, MySQL, and SQLite.
Other examples:
- Django ORM
- Pony ORM
- Peewee
- Tortoise ORM
ActiveRecord (Ruby)
ActiveRecord is a popular ORM tool for Ruby programming language. It provides a set of conventions for mapping object-oriented models to relational databases and supports multiple databases such as MySQL, PostgreSQL, and SQLite.
Other examples:
- Sequel
- DataMapper
- ROM
- Ohm
Entity Framework (C#)
Entity Framework is a popular ORM tool for C# programming language. It provides a set of APIs for working with databases and supports multiple databases such as SQL Server, MySQL, and Oracle.
Other examples:
- NHibernate
- Dapper
- LLBLGen Pro
- Telerik Data Access
- LINQ to SQL
Doctrine (PHP)
Doctrine is a popular ORM tool for PHP programming language. It provides a set of APIs for working with databases and supports multiple databases such as MySQL, PostgreSQL, and SQLite.
Other examples:
- Propel
- RedBeanPHP
- CakePHP
- PHP ActiveRecord
By using ORM, developers can work with objects instead of tables, reducing code complexity, improving maintainability, and increasing productivity. With the many ORM tools available in various programming languages, developers can choose the one that best fits their needs.