Method: ActiveRecord::QueryMethods#in_order_of

Defined in:

activerecord/lib/active_record/relation/query_methods.rb

#in_order_of(column, values, filter: true) ⇒ Object

Applies an ORDER BY clause based on a given column, ordered and filtered by a specific set of values.

User.in_order_of(:id, [1, 5, 3])
# SELECT "users".* FROM "users"
#   WHERE "users"."id" IN (1, 5, 3)
#   ORDER BY CASE
#     WHEN "users"."id" = 1 THEN 1
#     WHEN "users"."id" = 5 THEN 2
#     WHEN "users"."id" = 3 THEN 3
#   END ASC

column can point to an enum column; the actual query generated may be different depending on the database adapter and the column definition.

class Conversation < ActiveRecord::Base
  enum :status, [ :active, :archived ]
end

Conversation.in_order_of(:status, [:archived, :active])
# SELECT "conversations".* FROM "conversations"
#   WHERE "conversations"."status" IN (1, 0)
#   ORDER BY CASE
#     WHEN "conversations"."status" = 1 THEN 1
#     WHEN "conversations"."status" = 0 THEN 2
#   END ASC

values can also include nil.

Conversation.in_order_of(:status, [nil, :archived, :active])
# SELECT "conversations".* FROM "conversations"
#   WHERE ("conversations"."status" IN (1, 0) OR "conversations"."status" IS NULL)
#   ORDER BY CASE
#     WHEN "conversations"."status" IS NULL THEN 1
#     WHEN "conversations"."status" = 1 THEN 2
#     WHEN "conversations"."status" = 0 THEN 3
#   END ASC

filter can be set to false to include all results instead of only the ones specified in values.

Conversation.in_order_of(:status, [:archived, :active], filter: false)
# SELECT "conversations".* FROM "conversations"
#   ORDER BY CASE
#     WHEN "conversations"."status" = 1 THEN 1
#     WHEN "conversations"."status" = 0 THEN 2
#     ELSE 3
#   END ASC

# File 'activerecord/lib/active_record/relation/query_methods.rb', line 717

def in_order_of(column, values, filter: true)
  model.disallow_raw_sql!([column], permit: model.adapter_class.column_name_with_order_matcher)
  return spawn.none! if values.empty?

  references = column_references([column])
  self.references_values |= references unless references.empty?

  values = values.map { |value| model.type_caster.type_cast_for_database(column, value) }
  arel_column = column.is_a?(Arel::Nodes::SqlLiteral) ? column : order_column(column.to_s)

  scope = spawn.order!(build_case_for_value_position(arel_column, values, filter: filter))

  if filter
    where_clause =
      if values.include?(nil)
        arel_column.in(values.compact).or(arel_column.eq(nil))
      else
        arel_column.in(values)
      end

    scope = scope.where!(where_clause)
  end

  scope
end