A function of Ruby on Rails that allows you to handle database data without writing SQL.
This is sometimes called ʻOR mapper
.
With Active Record, you can handle data with simple methods without writing SQL statements.
By the way, regardless of Rails, the PHP framework also uses this OR mapper.
User.all
users = User.all
Get information for all users.
User.find
user = User.find(1)
Get the record of the user whose primary key matches.
User.find_by
user = User.find_by(name: 'gorira')
Get the first record that the data in the column matches under the specified conditions.
User.first
user = User.first
Get the first record of the user.
User.where
user = User.where(name: 'takeshi')
Get all records that match the conditions.
User.pluck
users_name = User.pluck(:name)
Get a specific column as an array.
User.order
user = User.order('id DESC')
Sorts based on the specified column.
User.delete_all
user = User.delete_all
Delete all data in the user table.
User.eager_load
user = User.eager_load(:items)
Outer join and get all the data.
https://railsguides.jp/active_record_basics.html
Recommended Posts