Query using sequelizejs returns undefined - node.js

Question

A model.js file contains this model :
exports.Conversations = db.sequelize.define('conversations', {
room_id: {
type: db.Sequelize.STRING
},
user_id: {
type: db.Sequelize.STRING
},
friend_id: {
type: db.Sequelize.STRING
},
}, {
timestamps: true,
createdAt:'created_at',
updatedAt:'updated_at',
deletedAt:'deleted_at',
freezeTableName: true // Model tableName will be the same as the model name
});
In query.js I have the following function :
exports.checkRoom = function(user_id,friend_id) {
models.Conversations.findOne({ where: { $or: [{user_id: user_id , friend_id: friend_id}, {user_id: friend_id , friend_id: user_id}] }} ).then(function(conversation) {
return conversation;
});
}
equivalent to:
SELECT
"id", "room_id", "user_id", "friend_id", "created_at", "updated_at"
FROM
"conversations" AS "conversations"
WHERE
(("conversations"."user_id" = '127' AND "conversations"."friend_id" = '124')
OR ("conversations"."user_id" = '124' AND "conversations"."friend_id" = '127'))
LIMIT 1;
When I do a call on that function in my cluster.js
var conversation = query.checkRoom(data.userId,data.friendId));
I get that conversation is undefined.
Found a couple of solutions to catch the object Promise but didnt worked.
Looking forward to your answers.
EDIT
Managed to do that but when calling the query I want to add that answer to a var so I can use it later on. If now i`m doing something like var
conversationId = query.checkRoom(data.userId, data.friendId).then(function(conversation) { return conversation.dataValues.id; })
I get that my var conversationId is [object Promise] .
How can I get and use that Promise outside .then() function ?

Answer 1

You're trying to use checkRoom() as a synchronous function, which it isn't (like most functions dealing with I/O in Node).
Instead, you should return the promise returned by findOne() and handle the resolving (and rejection) of that promise in your calling code:
// query.js
exports.checkRoom = function(user_id, friend_id) {
return models.Conversations.findOne({ where: { $or: [{user_id: user_id , friend_id: friend_id}, {user_id: friend_id , friend_id: user_id}] }} );
}
// calling code
query.checkRoom(data.userId, data.friendId).then(function(conversation) {
// do something with the database result
...
})