Module: CompositePrimaryKeys::ActiveRecord::QueryMethods

Included in:
CompositeRelation
Defined in:
lib/composite_primary_keys/relation/query_methods.rb

Instance Method Summary collapse

Instance Method Details

#reverse_sql_order(order_query) ⇒ Object 



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# File 'lib/composite_primary_keys/relation/query_methods.rb', line 4

def reverse_sql_order(order_query)
  if order_query.empty?
    # CPK
    # return [table[primary_key].desc] if primary_key

    if primary_key
      # break apart CPKs
      return primary_key.map do |key|
        table[key].desc
      end
    else
      raise IrreversibleOrderError,
            "Relation has no current order and table has no primary key to be used as default order"
    end
  end

  order_query.flat_map do |o|
    case o
    when Arel::Attribute
      o.desc
    when Arel::Nodes::Ordering
      o.reverse
    when String
      if does_not_support_reverse?(o)
        raise IrreversibleOrderError, "Order #{o.inspect} can not be reversed automatically"
      end
      o.split(",").map! do |s|
        s.strip!
        s.gsub!(/\sasc\Z/i, " DESC") || s.gsub!(/\sdesc\Z/i, " ASC") || (s << " DESC")
      end
    else
      o
    end
  end
end