def exec(*args, &block)
      if current = Thread.current[:squirm_connection]
        current.exec(*args, &block)
      else
        use {|conn| conn.exec(*args, &block)}
      end
    end
def exec(*args, &block)
      if current = Thread.current[:squirm_connection]
        current.exec(*args, &block)
      else
        use {|conn| conn.exec(*args, &block)}
      end
    end
Executes the query and passes the result to the block you specify.