MongoDB搜索在一系列ID中，使用Include不起作用
我有这个模型：
const NeighborSchema = new Schema({
friends: [
{
type: Schema.Types.ObjectId,
ref: "users",
},
],
date: {
type: Date,
default: Date.now,
},
});
module.exports = Neighbor = mongoose.model("neighbor", NeighborSchema);
我正在尝试查看所有邻居朋友中是否存在朋友：
const mongoose = require("mongoose");
const ObjectId = mongoose.Types.ObjectId;
const testIncludes = async () => {
let neighbors = await Neighbor.find();
let friends_ids = [];
neighbors.map((neighbor) => {
const { friends } = neighbor;
friends_ids = [...friends_ids, ...friends];
});
// Returns false for this
const element_to_search = ObjectId("60dcbb29118ea36a4f3ce229");
// Returns false for this
// const element_to_search = "60dcbb29118ea36a4f3ce229";
let is_element_found = friends_ids.includes(element_to_search);
};
// Returns false in both cases
testIncludes();
即使，element_to_search是直接从返回的friends_ids_ids array的列表中直接拍摄的尝试使用include搜索它，它由于某种原因返回false，无论我是搜索为string还是object> ObjectiD /代码>。
知道发生了什么事吗？
I have this model:
const NeighborSchema = new Schema({
friends: [
{
type: Schema.Types.ObjectId,
ref: "users",
},
],
date: {
type: Date,
default: Date.now,
},
});
module.exports = Neighbor = mongoose.model("neighbor", NeighborSchema);
I am trying to see if a friend exists in friends of all neighbors:
const mongoose = require("mongoose");
const ObjectId = mongoose.Types.ObjectId;
const testIncludes = async () => {
let neighbors = await Neighbor.find();
let friends_ids = [];
neighbors.map((neighbor) => {
const { friends } = neighbor;
friends_ids = [...friends_ids, ...friends];
});
// Returns false for this
const element_to_search = ObjectId("60dcbb29118ea36a4f3ce229");
// Returns false for this
// const element_to_search = "60dcbb29118ea36a4f3ce229";
let is_element_found = friends_ids.includes(element_to_search);
};
// Returns false in both cases
testIncludes();
Even though, element_to_search was taken directly from list of returned friends_ids array, when I try to search it using include, it returns false for some reason, whether I search it as a String or as an ObjectId.
Any idea what's going on?
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array.prototype.在内，将每个元素与样品进行比较，直到找到匹配为止。仅当对象引用类的同一实例时，才被认为是相等的。当您调用构造函数
const element_to_search = ObjectID（“ 60dcbb29118ea36a4f3ce229”）;它创建了一个从未在数组中的新实例，即使其值相同。您需要比较标量。字符串例如：
或者在首先构建
friends_ids时施放字符串，以避免在数组上进行额外的循环。Array.prototype.includes compares each element against the sample until it finds a match. Objects are considered equal only if they reference the same instance of the class. When you call a constructor
const element_to_search = ObjectId("60dcbb29118ea36a4f3ce229");it creates a new instance which has never been in the array, even if its value is the same.You need to compare scalars. Strings for example:
or cast it strings when you build up the
friends_idsat the first place to avoid the extra loop over the array.