type_condition

# File activerecord/lib/active_record/base.rb, line 1838
        def type_condition(table_alias=nil)
          quoted_table_alias = self.connection.quote_table_name(table_alias || table_name)
          quoted_inheritance_column = connection.quote_column_name(inheritance_column)
          type_condition = subclasses.inject("#{quoted_table_alias}.#{quoted_inheritance_column} = '#{sti_name}' ") do |condition, subclass|
            condition << "OR #{quoted_table_alias}.#{quoted_inheritance_column} = '#{subclass.sti_name}' "
          end

          " (#{type_condition}) "
        end