custom visitor

gistfile1.txt

module Arel
  module Visitors
    class MyWhereSsqlWithoutSql < Arel::Visitors::ToSql
      def initialize(inner_visitor, *args, &block)
        @inner_visitor = inner_visitor
        super(*args, &block)
      end

      private

      def visit_Arel_Nodes_SelectCore o, collector
        collector << ""
        wheres = o.wheres.map do |where|
          Nodes::SqlLiteral.new(@inner_visitor.accept(where, collector.class.new).value)
        end
        inject_join wheres, collector, ' AND '
      end
    end
  end
end

module Arel
  class SelectManager < Arel::TreeManager
    def where_sql_without_where(engine=Table.engine)
      return if @ctx.wheres.empty?
      viz = Visitors::MyWhereSsqlWithoutSql.new(engine.connection.visitor, engine.connection)
      Nodes::SqlLiteral.new viz.accept(@ctx, Collectors::SQLString.new).value
    end
  end
end

### And then to run it:

>> Lead.where(status: 1).arel.where_sql_without_where
=> "\"leads\".\"status\" = $1"