如何在MongoDB中获取日期中的第一个和最后一个元素以及其他元素？

db.collection.aggregate([
  {
    $project: {
      year: { $year: "$dateField" },
      month: { $month: "$dateField" },
      day: { $dayOfMonth: "$dateField" }
    }
  }
])

db.collection.aggregate([
  {
    $group: {
      _id: null,
      firstDate: { $min: "$dateField" }
    }
  }
])

db.collection.aggregate([
  {
    $group: {
      _id: null,
      lastDate: { $max: "$dateField" }
    }
  }
])

db.collection.aggregate([
  {
    $group: {
      _id: null,
      firstDate: { $min: "$dateField" },
      lastDate: { $max: "$dateField" },
      count: { $sum: 1 }
    }
  }
])