[Rails] Common CRUD methods

Create Use create Use new and save Read Use find_by Use where Update Use save Use update Use update_all use update_columns Delete Use destroy Use destroy_by Use destroy_all Related Articles

Create

Use `create`

user = User.create(name: "David", occupation: "Code Artist")

Use `new` and `save`

user = User.new
user.name = "David"
user.occupation = "Code Artist"
user.save

Read

Use `find_by`

This is useful and should be used to find only one record by the query.

# return the first user named David
david = User.find_by(name: 'David')

Use `where`

It returns an array of records.

# find all users named David who are Code Artists and sort by created_at in reverse chronological order
users = User.where(name: 'David', occupation: 'Code Artist').order(created_at: :desc)

Update

Use `save`

user = User.find_by(name: 'David')
user.name = 'Dave'
user.save

Use `update`

user = User.find_by(name: 'David')
user.update(name: 'Dave')

Using update will let failure pass silently. So it should be avoided.

Instead use update!.

user = User.find_by(name: 'David')
user.update(name: 'Dave')

Use `update_all`

Update several records at the same time.

User.update_all "max_login_attempts = 3, must_change_password = 'true'"

use `update_columns`

It does not trigger callbacks!

Delete

Dangerous operation!

Use `destroy`

user = User.find_by(name: 'David')
user.destroy

Use `destroy_by`

# find and delete all users named David
User.destroy_by(name: 'David')

Use `destroy_all`

# delete all users
User.destroy_all

https://guides.rubyonrails.org/active_record_basics.html

https://marcgg.com/blog/2020/04/08/rails-update-bang/