MongoDB:如何查找/删除两个或多个连续的重复项？

db.myCollection.aggregate([
  {
    $group: {
      _id: "$value",
      count: { $sum: 1 },
      docs: { $push: "$$ROOT" }
    }
  },
  {
    $match: {
      count: { $gt: 1 }
    }
  },
  {
    $unwind: "$docs"
  },
  {
    $sort: { "docs._id": 1 }
  },
  {
    $group: {
      _id: "$_id",
      docs: { $push: "$docs" }
    }
  },
  {
    $project: {
      _id: 0,
      value: "$_id",
      count: { $size: "$docs" },
      firstDoc: { $arrayElemAt: ["$docs", 0] }
    }
  }
])

db.myCollection.aggregate([
  {
    $group: {
      _id: "$value",
      count: { $sum: 1 },
      docs: { $push: "$$ROOT" }
    }
  },
  {
    $match: {
      count: { $gt: 1 }
    }
  },
  {
    $unwind: "$docs"
  },
  {
    $sort: { "docs._id": 1 }
  },
  {
    $group: {
      _id: "$_id",
      docs: { $push: "$docs" }
    }
  },
  {
    $project: {
      _id: 0,
      value: "$_id",
      count: { $size: "$docs" },
      firstDoc: { $arrayElemAt: ["$docs", 0] }
    }
  },
  {
    $unwind: "$docs"
  },
  {
    $match: {
      _id: { $ne: "$$ROOT._id" }
    }
  },
  {
    $replaceRoot: "$$ROOT.docs"
  }
]).forEach(function(doc) {
  db.myCollection.deleteOne({ _id: doc._id });
});