Improving ActiveRecord Select Column Rename in Rails

In this blog post, we’ll explore a more idiomatic way of renaming columns in Rails using ActiveRecord’s select method. This approach enhances readability and takes advantage of Rails’ powerful features.

Code Snippet

Here’s a comparison of the two methods:

# ❌ Incorrect or less preferred way
Project.select("deleted_at AS deletion_timestamp")

# ✅ Correct or preferred way
Project.select(projects: { deleted_at: :deletion_timestamp })

Explanation

Less Preferred Method

Project.select("deleted_at AS deletion_timestamp")

• Description: This line uses a raw SQL string to rename the column deleted_at to deletion_timestamp.
• Drawbacks:
  • Readability: Embedding SQL directly into your ActiveRecord queries can make the code harder to read and maintain, especially for those unfamiliar with SQL.
  • Database Independence: Direct SQL strings can reduce the portability of your code if you switch databases that have different SQL dialects.

Preferred Method

Project.select(projects: { deleted_at: :deletion_timestamp })

• Description: This approach uses Rails’ built-in capabilities to rename the column deleted_at to deletion_timestamp.
• Advantages:
  • Readability: The syntax is more Ruby-like and easier for Rails developers to understand.
  • Maintainability: It leverages Rails conventions, making the codebase easier to maintain and reduce potential errors.
  • Database Independence: By avoiding raw SQL, the code is more adaptable to different database backends that Rails might support.

Conclusion

The adoption of Rails conventions not only enhances the idiom of your code but also offers advantages in terms of readability and maintainability. When working with ActiveRecord, it’s often best to utilize its full potential rather than falling back on raw SQL unless absolutely necessary. This approach ensures your Rails applications remain robust and easy to manage over time.