如何在mongodb查询中嵌入日期到时间戳的转换？

db.collection.aggregate([
  {
    $addFields: {
      timestamp: {
        $toDate: {
          $dateFromParts: {
            year: { $year: "$dateField" },
            month: { $month: "$dateField" },
            day: { $dayOfMonth: "$dateField" },
            hour: { $hour: "$dateField" },
            minute: { $minute: "$dateField" },
            second: { $second: "$dateField" }
          }
        }
      }
    }
  }
])