How to do a query using dot( . ) through Mongoose in Node.js and How to add an empty array - arrays

Question

I have the following schema:
var userSchema = new Schema({
userID: Number,
userName: String,
userEmail: String,
teams:Array,
socialMedias:
{
fbUID: String,
googleUID: String,
twitter: String }
});
First, How can I add an empty array? Is it right the way I am doing in the following?
teams:{},
Second, I am trying to do a query using Mongoose in my Node.js but I am getting an error in the dot ('.'):
This is my document I am saving:
var user = new users({
userID: id, //give the id of the next user in Dbase
userName: userName,
userEmail: 'userEmail',
teams:{},
socialMedias: [{socialMediaType: socialMediaID}]
});
where userName, socialMediaType and socialMediaID are parameters of a function.
So, after I add this doc, I am trying to do the following query:
function searchUser(socialMediaID, socialMediaType){
var user
users.findOne({socialMedias.socialMediaType: socialMediaID}, function(err, userFound){
if(err) return handleError(err);
user = userFound;
});
//what does MongoDb return if it does not find the document?
return user;
}
but I am getting an error in this :
socialMedias.socialMediaType
So, how can I do this query?
I tried to find in Mongoose Documentation but I did not find.
Thank you for your understanding.

Answer 1

There's a number of issues here that you are likely running into.
First, teams is an array property, but you're assigning an object to it. You need to do something like this:
var user = new users({
userID: id, //give the id of the next user in Dbase
userName: userName,
userEmail: 'userEmail',
teams:[],
socialMedias: [{socialMediaType: socialMediaID}]
});
Second, if socialMediaType is passed in as a function param, you can't use it like you're doing. You need to do something like this:
var socialMedias = {};
socialMedias[socialMediaType] = socialMediaID;
var user = new users({
userID: id, //give the id of the next user in Dbase
userName: userName,
userEmail: 'userEmail',
teams:[],
socialMedias: [socialMedias]
});
Third your findOne is not going to work as is. From what I can gather of your intention here, you need something like this:
function searchUser(socialMediaID, socialMediaType){
var user
var query = {};
query["socialMedias."+socialMediaType] = socialMediaID;
users.findOne(query, function(err, userFound){
if(err) return handleError(err);
user = userFound;
});
//what does MongoDb return if it does not find the document?
return user;
}
But fourth, even that won't work because you are synchronously returning user from a method that performs and asynchronous operation. There are various ways to solve that, but you can start by reading up about promises, or passing a callback function into searchUser.