Introduction to ‘Active Record’ in Ruby on Rails

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Hi guys, I hope to cover on how we can use active record inside a rails application to interact with databases from few articles. This is the first one of the series.

Here, I hope to take an introduction to Active Record. First things first, let’s discuss about the definition for the ‘Active Record’.

‘Active Record’ ?? 🤔

Ruby on Rails Active Record

‘Active Record’ is the M in MVC. M means Model & MVC means Model — View-Controller, which is a pattern that rails is built upon. In this case, an Active Record serves as the ORM system for rails.

What is ORM ?

ORM means Object Relational Mapping. It allows developers to interact with databases using the programming language. It’s a programming technique used to convert data between incompatible type systems in OOP languages. It’s essentially a way to abstract the database interactions and operations so that the developer can work with objects rather than dealing with those messy SQL queries directly. This is how Abstraction (a OOP concept) is used in rails.

Each programming ecosystem typically has one or more popular ORM frameworks that are widely used within that community. These frameworks not only make database interactions easier but also integrate well with other tools and libraries in the ecosystem.

Active Record & Rails MVC

Active Record is a crucial component of the Ruby on Rails framework, primarily fitting into the Model layer of the MVC architecture. If you want to get to know more about MVC, take a visit to this article .

What Active Record does in rails?

1. Data Handling: Active Record is responsible for data handling and encapsulation.
2. Data Abstraction : It abstracts database interactions and handles all the SQL generation and execution.
3. Business Logic: Business logic and data validation are embedded in within Active Record models.
4. DB interaction: Active Record handles all database interactions seamlessly behind the scenes.
5. Life cycle events: Active Record models can define callbacks that hook into the life cycle of DB records, such as before and after creation, update or destruction.
6. Migration management: Rails uses Active Record migrations to handle changes in the DB schema overtime.

Let’s go through an example 👉

This flow ensures that each part of the application only handles specific tasks. Hence Active Record has become the backbone of a Rails Application by managing the data model, ensuring that the data-related logic is efficiently handled, while also maintaining a separation of concerns as advocated by the MVC design pattern.

Benefits & Limitations of Active Record

1. Ease of use : It avoids the need of writing verbose SQL queries.
2. Rapid Development : It automates CRUD operations, handles DB schema migrations, integrates with Rails’ scaffolding to quickly generate the necessary mvc s.
3. Convention over Configuration : It can automatically map between DB tables and Ruby classes.
4. Integrated Validations : It provides a rich validation framework that is both simple to use and highly customizable.
5. Association & Relationship Management : It simplifies the management of DB relationships through intuitive association methods
6. Automatic Schema Migrations : Active Record Migrations allow developers to evolve the DB schema overtime in a consistent and easy way.
7. Life cycle Callbacks : It supports callbacks during the whole life cycle of the object.
8. Performance issues : For every large datasets or extremely complex queries , the SQL generated by Active Record might not be as efficient as hand crafted SQL queries.
9. Complexity in scaling : High traffic applications may face challenges due to the object-heavy nature of ORM and the overheads associated with it.
10. Limited Flexibility : Sometimes it may be not flexible if we want to step outside the idiomatic ways of doing things in rails.
11. Learning Curve : Mastering more advanced features and optimizations requires a deeper understanding of both SQL and Active Record internals.
12. Dependency on Active Record : If you’re planning to heavily depend on Active Records, it may be a major conflict on switching to a different storage solution in the future. This is called as “Active Record trap”. Hence we have to make sure to not the business logic too tightly coupled with the ORM layer.
13. Potential for N+1 Query Problems : If relationships are not properly managed, it’s easy to fall into the N+1 query problem.

Active Record is a powerful tool that can greatly enhance productivity and maintainability in many web applications. However, developers should be aware of its limitations and consider using additional strategies, such as database indexing, query optimization, and sometimes raw SQL, to mitigate performance issues, especially in larger, more complex applications.

Need to keep every article in short (below 5 mins read). Let’s discuss about ‘Setting up Active Record’ in the next article. See you soon. 👋