Rails Find All

If you are working with Ruby on Rails, you will often need to find all records of a specific model or a subset of records that match a specific condition. This can be done using the find_all method.

The find_all method returns an array of all records that match a specific condition. This method is most commonly used with ActiveRecord, but can also be used with other Ruby collections.

Syntax

The syntax for using find_all with ActiveRecord is:

ModelName.all

This will return an array of all records for the given model.

ModelName.find_all_by_column_name(value)

This will return an array of all records that match the given value for the specified column.

ModelName.where(column_name: value)

This will return an array of all records that match the given value for the specified column using ActiveRecord query interface.

Examples

Let's say we have a User model with the following attributes:

class User < ApplicationRecord
  name: string
  age: integer
  email: string
end

Find all records

To get all records for the User model, we can use the all method:

users = User.all

This will return an array of all users in the database.

Find all records with a specific age

To get all records for the User model with a specific age, we can use the where method:

users = User.where(age: 30)

This will return an array of all users in the database with an age of 30.

Find all records with a specific age using ActiveRecord query interface

To get all records for the User model with a specific age using ActiveRecord query interface, we can also use the where method:

users = User.where("age = ?", 30)

This will return an array of all users in the database with an age of 30.

Find all records with a specific name

To get all records for the User model with a specific name, we can use the find_all_by_name method:

users = User.find_all_by_name("John")

This will return an array of all users in the database with a name of "John".

Conclusion

In conclusion, the find_all method is a powerful tool in Ruby on Rails that allows you to easily retrieve all records or subsets of records from a model. By using this method with ActiveRecord query interface, you can build complex queries to get exactly the data you need.