Find all documents in one model using property of another model in Mongoose-CodePudding

I have two models named post and user. The Post Model is as defined below:

const postSchema = new mongoose.Schema({
    _id: {
        type: mongoose.Types.ObjectId,
        auto: true,
    },
    userId: {
        type: mongoose.Types.ObjectId,
        required: true
    },
    header: {
        type: String,
        max: 1024,
        required: true,
    },
    body: {
        type: String,
    },
    tags: {
        type: Array,
        default: []
    }
});

The user model is as defined below:

const userSchema = new mongoose.Schema({
    _id: {
        type: mongoose.Types.ObjectId,
        auto: true,
    },
    username: {
        type: String,
        required: true,
        max: 255,
    },
    email: {
        type: String,
        required: true,
        max: 255,
    },
    password: {
        type: String,
        required: true,
        min: 6,
        max: 1024,
    },
    role: {
        type: String,
        required: true,
        max: 255,
    },
    tags: {
        type: Array,
        default: []
    }
});

I need to get all the posts that have tags similar to User Tags. That means if User Tags has tag-1, and tag-2 I need all the posts which have tag-1 and tag-2 or just tag-1 or tag-2. At present, I am doing as below.

    tagsInfo = [];
    await User.findById(req.body.userId).then((userInfo, err) => {
        for (let i = 0; i < userInfo.tags.length; i  ) {
            tagsInfo.push(userInfo.tags[i]);
        }
    });
    postsArray = [];
    for (let i = 0; i < tagsInfo.length; i  ) {
        await Post.find({ tags: tagsInfo[i] }).then((posts, err) => {
            postsArray = [...postsArray, posts];
        });
    }

I was just wondering if there is a better way to get all the posts that have user tags.

CodePudding user response：

Not sure why are you pushing the user tags to tagsInfo array. but can you do

let user = await User.findById(req.body.userId);

You can use $in operator in order to avoid the second loop. You can put if check if needed (I'm assuming findById returns value).

let Post = await Post.find({
    tags: {
        "$in": user.tags
    }
});

If you are doing async/await don't use then/catch syntax. use one not both