Object-Relational Mapping (ORM) is a programming technique that allows developers to work with relational databases using object-oriented programming languages. The fundamental idea behind ORM is to create a "virtual" object-oriented database that mirrors the structure and behavior of the underlying relational database.
Here's an overview of how ORM works:
Mapping Database Tables to Objects: ORM frameworks typically provide tools for mapping database tables to object classes in the application code. Each row in a database table corresponds to an instance of a class, and each column in the table corresponds to an attribute of the class.
Encapsulation of Data and Behavior: ORM allows developers to encapsulate both the data structure (columns) and the behavior (methods) associated with database records within object classes. This makes it easier to work with database records using familiar object-oriented techniques.
CRUD Operations: ORM frameworks provide methods for performing CRUD (Create, Read, Update, Delete) operations on database records using object-oriented syntax. Developers can create, retrieve, update, and delete records using method calls on objects, rather than writing SQL queries directly.
Relationship Mapping: ORM frameworks support defining and managing relationships between different database tables using object associations. This allows developers to express one-to-one, one-to-many, and many-to-many relationships between objects in their application code.
Query Interface: ORM frameworks typically provide a query interface for constructing database queries using a high-level, domain-specific language (DSL). Developers can use method chaining and other syntactic constructs to build complex queries, which are then translated into SQL queries by the ORM framework.
Data Validation and Transformation: ORM frameworks often include features for validating data before it is saved to the database and for transforming data between its representation in the application code and its representation in the database. This helps ensure data integrity and consistency.
ORM frameworks abstract away the details of database interaction, allowing developers to focus on application logic rather than database management. They promote code organization, reduce boilerplate code, and improve productivity by providing a higher-level, object-oriented interface for working with databases. Ruby on Rails' ActiveRecord, Django's ORM, and Hibernate for Java are popular examples of ORM frameworks.
Object-Relational Mapping (ORM) is a programming technique that allows developers to work with relational databases using object-oriented programming languages. The fundamental idea behind ORM is to create a "virtual" object-oriented database that mirrors the structure and behavior of the underlying relational database.
Here's an overview of how ORM works:
Mapping Database Tables to Objects: ORM frameworks typically provide tools for mapping database tables to object classes in the application code. Each row in a database table corresponds to an instance of a class, and each column in the table corresponds to an attribute of the class.
Encapsulation of Data and Behavior: ORM allows developers to encapsulate both the data structure (columns) and the behavior (methods) associated with database records within object classes. This makes it easier to work with database records using familiar object-oriented techniques.
CRUD Operations: ORM frameworks provide methods for performing CRUD (Create, Read, Update, Delete) operations on database records using object-oriented syntax. Developers can create, retrieve, update, and delete records using method calls on objects, rather than writing SQL queries directly.
Relationship Mapping: ORM frameworks support defining and managing relationships between different database tables using object associations. This allows developers to express one-to-one, one-to-many, and many-to-many relationships between objects in their application code.
Query Interface: ORM frameworks typically provide a query interface for constructing database queries using a high-level, domain-specific language (DSL). Developers can use method chaining and other syntactic constructs to build complex queries, which are then translated into SQL queries by the ORM framework.
Data Validation and Transformation: ORM frameworks often include features for validating data before it is saved to the database and for transforming data between its representation in the application code and its representation in the database. This helps ensure data integrity and consistency.
ORM frameworks abstract away the details of database interaction, allowing developers to focus on application logic rather than database management. They promote code organization, reduce boilerplate code, and improve productivity by providing a higher-level, object-oriented interface for working with databases. Ruby on Rails' ActiveRecord, Django's ORM, and Hibernate for Java are popular examples of ORM frameworks.