How to Use the Rails new & save Methods

09/21/2021

Contents

In this article, you will learn how to use the Rails new and save methods.

Using the Rails new and save methods

In Ruby on Rails, the new method is used to create a new instance of a model object, and the save method is used to persist that object to the database.

Here is an example of how to use these methods:

Define the Model

First, you need to define a model that represents a table in your database. For example, if you wanted to create a User model, you could run the following command in your terminal:

rails generate model User name:string email:string

This will create a migration file that you can run to create the users table in your database.

Instantiate the Object

Once you have a model defined, you can create a new instance of that object using the new method. For example, to create a new user object, you could do the following:

user = User.new(name: "John Smith", email: "john@example.com")

This will create a new user object with the specified name and email attributes.

Save the Object

After you have created a new object, you can save it to the database using the save method. For example:

user.save

This will save the user object to the database.

Handling Errors

The save method will return true if the object was successfully saved, or false if there was an error. You can check if the save was successful using the valid? method. For example:

if user.valid?
  user.save
else
  # handle errors
end

If the valid? method returns false, you can check the errors attribute to see what went wrong:

user.errors.full_messages

This will return an array of error messages that can be displayed to the user.