How to Use the Rails find_by Method

09/20/2021

Contents

In this article, you will learn how to use the Rails find_by method.

Rails find_by Method

The find_by method is a convenient way to query for a single record in a Rails model based on a specific attribute value. Here’s an example of how to use it:

Suppose you have a User model with attributes id, name, and email. To find a user with a specific email address, you can use the following code:

user = User.find_by(email: 'example@example.com')

This will search the users table for a record with an email attribute equal to ‘example@example.com’, and return the first record that matches. Note that find_by returns nil if no matching record is found.

You can also use find_by with multiple attributes, like this:

user = User.find_by(name: 'John', email: 'john@example.com')

This will search the users table for a record with a name attribute equal to ‘John’ and an email attribute equal to ‘john@example.com’, and return the first record that matches.

In addition to find_by, Rails provides several other methods for querying records based on attribute values, including find_by! (which raises an exception if no matching record is found), where (which returns a collection of records), and more.