How to merge two schemas in mongodb - mongodb

Question

I have a post schema and user schema and I want to merge them together. I waant to know how to do it. So far I have this code but I keep returning promises. When I add then after the .map, I get no result. Any help would be appreciated
let posts = await Post.find();
console.log(posts);
let test = await posts.map(async(post) => {
const creator = await User.findOne({token: post.creator});
var username = null;
if(creator){
username = creator.username;
}
return {...post._doc, username: username};
});
return posts;

Answer 1

you can use q and async module
const q = require("q");
const async = require("async");
async function mainFunction() {
try {
let posts = await Post.find();
let result = await getUser(posts);
console.log(result)
} catch (error) {
console.error(error);
return { error: error };
}
}
async function getUser (posts) {
let defer = q.defer;
let test = [];
async.eachSeries(posts,async (post) => {// like loop
try {
let creator = await User.findOne({ token: post.creator });
var username = null;
if (creator) {
username = creator.username;
}
test.push({ ...post._doc, username: username });
} catch (error) {
console.log(error);
}
},() => {//callback
console.log("finish loop");
defer.resolve(test); // when finished loop return result
}
);
return defer.promise;
};