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Object-Relational Mapping

Definition

Object-Relational Mapping (ORM) is a programming technique that allows for the conversion or mapping of data between incompatible type systems such as object-oriented programming languages and relational databases. This allows developers to interact with databases using object-oriented syntax, thus simplifying data creation, manipulation and access. It essentially creates a ‘virtual object database’ that can be utilized within the programming language.

Phonetic

The phonetic pronunciation of “Object-Relational Mapping” is:ˈɒbdʒekt rɪˈleɪʃənəl ˈmæpɪŋ

Key Takeaways

  1. Abstraction of database interactions: Object-Relational Mapping (ORM) tools provide an abstraction of database interactions by allowing developers to work with objects instead of SQL, which makes development faster and more efficient, particularly when dealing with complex databases structures.
  2. Reduction of code complexity: Because ORM allows developers to write code in their preferred programming language, it eliminates the need for repetitive SQL code, thereby reducing the overall code complexity.
  3. Database independence: One of the significant advantages of ORM is its ability to make applications database independent. This means that the underlying database can be switched or altered without the need for major changes to the application code.

Importance

Object-Relational Mapping (ORM) is a significant technological concept because it functions as the bridge between the object-oriented programming languages and relational databases. Given the fundamental differences in how data is stored and manipulated in both models, ORM becomes crucial since it allows developers to interact with their databases like they would with SQL. It abstracts and encapsulates the code necessary for querying data, thereby promoting code efficiency and reusability. This leads to improved productivity as it removes the need for repetitive and error-prone SQL code, fostering seamless data manipulation and retrieval. ORM also offers additional important features such as data caching, lazy loading, and transaction management, thereby ensuring a simplified, streamlined, and effectively managed database interaction process.

Explanation

Object-Relational Mapping, often abbreviated as ORM, is a programming technique that aids in converting data between incompatible type systems using object-oriented programming languages. The primary objective of ORM is to address and bridge the gap that exists between the object and relational world, which thus allows developers to manipulate data without having to consider how the data is stored in the actual database.ORM is extensively utilized for simplifying data creation, manipulation, and access. It does this by ‘wrapping’ the raw SQL queries within methods, which effectively hides the complexity of data exchange between a relational database and an object-oriented application. This means that, with ORM, developers can perform CRUD operations (Create, Read, Update, Delete) without needing to write SQL code. By doing so, ORM can aid in boosting productivity since it eliminates the need for mundane, repeatable code, hence freeing up developers to focus more on the business logic of the application.

Examples

1. Django ORM: Django is a high-level Python framework that includes an ORM. The Django ORM allows developers to interact with their database, like they would with SQL. In other words, it’s a way to create, retrieve, update and delete records in your database using Python.2. Hibernate in Java: Hibernate is a popular ORM framework in Java that simplifies the task of interacting with databases. It maps Java classes to database tables and from Java data types to SQL data types. Hibernate also provides query service, which allows developers to use SQL-like language to communicate with databases. 3. Entity Framework in .NET: Entity Framework (EF) is another example of an ORM. This .NET tool allows developers to work with data in the form of domain-specific objects and properties, eliminating most of the data-access code developers usually need to write. With Entity Framework, developers can focus more on business logic and less on data access fundamentals.

Frequently Asked Questions(FAQ)

**Q1: What is Object-Relational Mapping (ORM)?**A1: Object-Relational Mapping (ORM) is a technique that connects the rich objects in an object-oriented language to the basic data structures of a relational database. It allows developers to interact with their database like they would with SQL.**Q2: How does ORM function in programming?**A2: ORM functions by transforming data from the database into OOP languages, allowing programmers to work with objects and properties instead of SQL queries. The ORM software will handle all the conversions, including data types and database connections.**Q3: Why is ORM important?**A3: ORM is important as it greatly simplifies the data manipulation process. It enables developers to create, read, update and delete database entries by manipulating programming language objects, without the need for SQL.**Q4: Which programming languages use ORM?**A4: Most modern programming languages use ORM tools. Some notable examples are Java, C#, PHP, Python, Ruby, and JavaScript. The ORM tools used in these languages include Hibernate, Entity Framework, SQLAlchemy, and ActiveRecord.**Q5: What is the difference between ORM and SQL?**A5: ORM and SQL are both tools used in database management. SQL or Structured Query Language is the actual language used to manage and manipulate databases. ORM, on the other hand, is a tool that translates SQL queries into a language more naturally used by developers like Java, Python, etc.**Q6: What are the benefits of using ORM?**A6: There are several benefits to using ORM. It provides a high level of abstraction from the underlying SQL, simplifies database manipulations, eliminates repetitive database-related coding and makes code more reusable. Importantly, ORM can also help to improve database application security by automatically escaping data and avoiding SQL injection attacks.**Q7: What are the limitations or disadvantages of ORM?**A7: The limitations of ORM include overhead and performance drawbacks because it’s mapping complex relationships between data. Complex transactions can become cumbersome and difficult to manage. Additionally, using ORM may very well mean a loss of control and flexibility compared to using SQL directly.

Related Tech Terms

  • Entity Framework
  • Database Abstraction Layer
  • Hibernate Framework
  • SQLAlchemy
  • NHibernate

Sources for More Information

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