class ApplicationRecord < ActiveRecord::Base
self.abstract_class = true
def self.use_index(index)
from("#{self.table_name} USE INDEX(#{index})")
end
end
ActiveRecord::Base.connection.tables
ActiveRecord::Base.connection.indexes("users")
ActiveRecord::Base.connection.indexes("users").pluck(:name)
Module
ActiveRecord::QueryMethods
Methods
from
from(value, subquery_name = nil)
Specifies table from which the records will be fetched. For example:
Topic.select('title').from('posts')
# SELECT title FROM posts
Can accept other relation objects. For example:
Topic.select('title').from(Topic.approved)
# SELECT title FROM (SELECT * FROM topics WHERE approved = 't') subquery
Topic.select('a.title').from(Topic.approved, :a)
# SELECT a.title FROM (SELECT * FROM topics WHERE approved = 't') a
GitHub - line 819
