将元素从$ pull移动到另一个数组 [英] Move elements from $pull to another array

问题描述

我在同一集合中有很多文档，如下所示:

I have many documents in the same collection that look like this:

{
  "_id": ObjectId("4d525ab2924f0000000022ad"),
  "array": [
    { id: 1, other: 23 },
    { id: 1, other: 21 },
    { id: 0, other: 235 },
    { id: 1, other: 765 }
  ],
  "zeroes": []
}

我希望他们看起来像这样:

and I want them to look like this:

{
  "_id": ObjectId("4d525ab2924f0000000022ad"),
  "array": [
    { id: 1, other: 23 },
    { id: 1, other: 21 },
    { id: 1, other: 765 }
  ],
  "zeroes": [
    { id: 0, other: 235 }
  ]
}

基本上，我希望能够提取数组中的某些元素并将其推到另一个数组中.我知道我可以使用$pull有条件地从数组中删除元素，但是可以重新放置这些拉出的元素吗?

Basically, I want to be able to pull some elements in an array, and push it to another array. I know I can use $pull to conditionally remove elements from an array, but is it possible to relocate these pulled elements?

推荐答案

不是.您可以使用光标进行这样的操作.

Not really. You can use cursor for operation like this.

db.foo.find({}).forEach(function(doc) {
    doc.zeros = doc.array.filter(function(x) { return x.id == 0 });
    doc.array = doc.array.filter(function(x) { return x.id != 0 });
    db.foo.save(doc)};
)

这篇关于将元素从$ pull移动到另一个数组的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！