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rails--rails/activerecord/lib/arel/nodes/table_alias.rb
Ryuta Kamizono 1ac40f16c5 Move Arel attribute normalization into arel_table
In Active Record internal, `arel_table` is not directly used but
`arel_attribute` is used, since `arel_table` doesn't normalize an
attribute name as a string, and doesn't resolve attribute aliases.

For the above reason, `arel_attribute` should be used rather than
`arel_table`, but most people directly use `arel_table`, both
`arel_table` and `arel_attribute` are private API though.

Although I'd not recommend using private API, `arel_table` is actually
widely used, and it is also problematic for unscopeable queries and
hash-like relation merging friendly, as I explained at #39863.

To resolve the issue, this change moves Arel attribute normalization
(attribute name as a string, and attribute alias resolution) into
`arel_table`.
2020-07-19 23:41:24 +09:00

31 lines
748 B
Ruby

# frozen_string_literal: true
module Arel # :nodoc: all
module Nodes
class TableAlias < Arel::Nodes::Binary
alias :name :right
alias :relation :left
alias :table_alias :name
def [](name)
relation.is_a?(Table) ? relation[name, self] : Attribute.new(self, name)
end
def table_name
relation.respond_to?(:name) ? relation.name : name
end
def type_cast_for_database(attr_name, value)
relation.type_cast_for_database(attr_name, value)
end
def type_for_attribute(name)
relation.type_for_attribute(name)
end
def able_to_type_cast?
relation.respond_to?(:able_to_type_cast?) && relation.able_to_type_cast?
end
end
end
end