[英]Find with array of IDs in mongoose
I make an API with Express.js and mongoose.我用 Express.js 和 mongoose 制作了 API。 I need to find users whose id is contained in an array.
我需要找到 id 包含在数组中的用户。
// the array of ids
const followedIds = follow.map((f) => f.followed);
console.log(followedIds);
// return [ '5ebaf673991fc602045ed47f', '5ebc6fb9af8add09edd842e9' ]
All IDs in this array exist.此数组中的所有 ID 都存在。
Then I do:然后我这样做:
User.where('_id').in(followedIds).exec()
.then((followedUser) => {
console.log('followedUser', followedUser);
// return []
});
followedUser
should have two users objects with the matching ids. followedUser
应该有两个具有匹配 id 的用户对象。
How can I resolve this?我该如何解决这个问题?
Thanks谢谢
PS: There is my User model PS:还有我的用户model
const mongoose = require('mongoose');
const user = new mongoose.Schema({
username: { type: String, required: true },
email: { type: String, required: true },
password: { type: String, required: true },
avatar: { type: String, default: '/images/avatar_default.jpg' },
banner: { type: String, default: '/images/banner_default.jpg' },
created_at: { type: Date, required: true },
deleted_at: { type: Date, required: false },
}, { versionKey: false });
module.exports = mongoose.model('user', user);
You can use an $in operator and provide an array of IDs as is to the mongo.您可以使用$in 运算符并向 mongo 提供一个 ID 数组。 Eg you can query the users that has specified IDs from the array:
例如,您可以从数组中查询具有指定 ID 的用户:
const followedUsers = await User.find({ _id: { $in: followedIDs } });
console.log(followedUsers);
But, make sure that your followedIDs
is an array of ObjectId
.但是,请确保您的
followedIDs
是ObjectId
的数组。 MongoDB stores _id
as an ObjectId
, not the string. MongoDB 将
_id
存储为ObjectId
,而不是字符串。
db.inventory.insertMany([
{ item: "journal", qty: 25, status: "A" },
{ item: "notebook", qty: 50, status: "A" },
{ item: "paper", qty: 100, status: "D" },
{ item: "planner", qty: 75, status: "D" },
{ item: "postcard", qty: 45, status: "A" }
]);
db.inventory.find({ _id: { $in: [ObjectId("your_id_here")] } });
To generate such an array from the array of strings, use map
:要从字符串数组生成这样的数组,请使用
map
:
const followedIDs = yourArrayWithIDAsString.map(ObjectId);
.in
method like .in
方法如
User.find().where('_id').in(followedIds)
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