I'm having two tables user and group, a manytomany relation between them, thereofre a third table group_has_user
given a user I'm trying to remove some groups,
I tried :
Model.User.findOne({
where: {
"id": POST.id
},
include: [Model.Project]
}).then(function (user) {
user.Project.destroy({
where:{
"id": ids
}
})
})
where id is the user id and ids, is a list of groups that I wan to
remove
but this code doesn't works, project is undefined, and also I don't think that what I want could be done this way, can anyone help ?
You can get the Projects you want to remove and then call the generated removeProject method on each project you got:
Model.User.findOne({
where: {
"id": POST.id
},
include: [Model.Project]
}).then(function (user) {
Model.Projcet.find({
where: {
id: {
[Op.in]: ids
}
}
}).then(projectsToRemove => {
projectsToRemove.forEach(p => {
await user.removeProject(p);
})
})
})
Source: Official documentation
Related
I have a structure like this:
{
_id: new ObjectId("634aa49f98e3a05346dd2327"),
filmName: 'Film number 1',
episodes: [
{
episodeName: 'Testing 1',
slugEpisode: 'testing-1',
_id: new ObjectId("6351395c17f08335f1dabfc9")
},
{
episodeName: 'Testing 2',
slugEpisode: 'testing-2',
_id: new ObjectId("6351399d9a2533b9be1cbab0")
},
],
},
{
_id: new ObjectId("634aa4cc98e3a05346dd232a"),
filmName: 'Film number 2',
episodes: [
{
episodeName: 'Something 1',
slugEpisode: 'something-1',
_id: new ObjectId("6367cce66d6b85442f850b3a")
},
{
episodeName: 'Something 2',
slugEpisode: 'something-2',
_id: new ObjectId("6367cd0e6d6b85442f850b3e")
},
],
}
I received 3 fields:
_id: Film _id
episodeId: Episode _id
episodeName: The content I wish to update
I tried to find a specific Film ID to get a specific film, and from then on, I pass an Episode ID to find the exact episode in the episodes array. Then, update the episodeName of that specific episode.
Here's my code in NodeJS:
editEpisode: async (req, res) => {
const { _id } = req.params
const { episodeId, episodeName } = req.body
try {
const specificResult = await Films.findOneAndUpdate(
{ _id, 'episodes._id': episodeId },
{ episodeName }
)
console.log(specificResult)
res.json({ msg: "Success update episode name" })
} catch (err) {
return res.status(500).json({ msg: err.message })
}
},
But what console.log display to me is a whole document, and when I check in MongoDB, there was no update at all, does my way of using findOneAndUpdate incorrect?
I'm reading this document: MongooseJS - Find One and Update, they said this one gives me the option to filter and update.
The MongoDB server needs to know which array element to update. If there is just one array element to update, here's one way you could do it. (I picked a specific element. You would use your req.params and req.body.)
db.films.update({
"_id": ObjectId("634aa4cc98e3a05346dd232a"),
"episodes._id": ObjectId("6367cd0e6d6b85442f850b3e")
},
{
"$set": {
"episodes.$.episodeName": "Something Two"
}
})
Try it on mongoplayground.net.
You can use the filtered positional operator $[<identifier>] which essentially finds the element or object (in your case) with a filter condition and updates that.
Query:
const { _id } = req.params
const { episodeId, episodeName } = req.body
await Films.update({
"_id": _id
},
{
$set: {
"episodes.$[elem].episodeName": episodeName
}
},
{
arrayFilters: [
{
"elem._id": episodeId
}
]
})
Check it out here for example purpose I've put ids as numbers and episode name to update as "UpdatedValue"
So when I query without attribute: exclude... it returns me the correct user, but when I insert that in the query it returns a completly different user. Here is the code that I'm inserting.
const user = await Users.findOne(
{
attributes: { exclude: ["password", "admin", "createdAt", "updatedAt"] },
},
{ where: { id: req.user.id } }
);
res.json({ user });
Any ideas why is this happening?
Thanks in advance
You'r passing the where condition to the second paramter, but according to the docs: https://sequelize.org/docs/v6/core-concepts/model-querying-finders/#findone
Model.findOne only has one parameter which is the query options.
Move your where condition into the object for the first parameter.
const user = await Users.findOne({
attributes: {
exclude: ["password", "admin", "createdAt", "updatedAt"],
},
where: { id: req.user.id },
});
res.json({ user });
I have two loopback models: user and backendUser. One (user) is stored with loopback and the other one (backendUser) is stored on a distant mysql database. They have a relation togerther based on a field user has (backendUserId) corresponding to the ID field of backendUser
There is a case where I get every user with its corresponding backendUser. But I would like to get the users depending on some backendUser values. Example: I need every user where the backendUser.role is 4.
I use this filter to have the expected result:
{ include: { relation: "backendUser", scope: { where: { "role" : 4 } } } }
My issue is that I get an array of every user but I only get related backendUser when they have role to 4. The where is only applying on backendUser not on the whole entity.
I don't know if it's clear, but I really need this.
Use the following:
{
where: {
role: 4,
include: {
relation: "backendUser",
scope: {
where: { "role": 4 }
}
}
}
}
{
where: {
// here specific object of query user
},
include: [
{
relation: 'backendUser',
scope: {
where: {
role: 4,
},
},
},
],
}
Say I have a collection of documents, each one managing a discussion between a teacher and a student:
{
_id,
teacherId,
studentId,
teacherLastMessage,
studentLastMessage
}
I will get queries with 3 parameters: an _id, a userId and a message.
I'm looking for a way to update the teacherLastMessage field or studentLastMessage field depending on which one the user is.
At the moment, I have this:
return Promise.all([
// if user is teacher, set teacherLastMessage
db.collection('discussions').findOneAndUpdate({
teacherId: userId,
_id
}, {
$set: {
teacherLastMessage: message
}
}, {
returnOriginal: false
}),
// if user is student, set studentLastMessage
db.collection('discussions').findOneAndUpdate({
studentId: userId,
_id
}, {
$set: {
studentLastMessage: message
}
}, {
returnOriginal: false
})
]).then((results) => {
results = results.filter((result) => result.value);
if (!results.length) {
throw new Error('No matching document');
}
return results[0].value;
});
Is there a way to tell mongo to make a conditional update, based on the field matched? Something like this:
db.collection('discussions').findOneAndUpdate({
$or: [{
teacherId: userId
}, {
studentId: userId
}],
_id
}, {
$set: {
// if field matched was studentId, set studentLastMessage
// if field matched was teacherId, set teacherLastMessage
}
});
Surely it must be possible with mongo 3.2?
What you want would require referencing other fields inside of $set. This is currently impossible. Refer to this ticket as an example.
First of all, your current approach with two update queries looks just fine to me. You can continue using that, just make sure that you have the right indexes in place. Namely, to get the best performance for these updates, you should have two compound indexes:
{ _id: 1, teacherId: 1 }
{ _id: 1, studentId: 1 }.
To look at this from another perspective, you should probably restructure your data. For example:
{
_id: '...',
users: [
{
userId: '...',
userType: 'student',
lastMessage: 'lorem ipsum'
},
{
userId: '...',
userType: 'teacher',
lastMessage: 'dolor sit amet'
}
]
}
This would allow you to perform your update with a single query.
Your data structure is a bit weird, unless you have a specific business case which requires the data the be molded that way i would suggest creating a usertype unless a user can both be a teacher and a student then keep your structure.
The $set{} param can take a object, my suggestion is to do your business logic prior. You should already know prior to your update if the update is going to be for a teacher or student - some sort of variable should be set / authentication level to distinguish teachers from students. Perhaps on a successful login in the callback you could set a cookie/local storage. Regardless - if you have the current type of user, then you could build your object earlier, so make an object literal with the properties you need based on the user type.
So
if(student)
{
var updateObj = { studentLastMsg: msg }
}
else
{
var updateObj = { teacherLastMsg: msg }
}
Then pass in your update for the $set{updateObj} I'll make this a snippet - on mobile
I'm trying to understand how best to perform a query over multiple entities using Sequelize and Node.js.
I have defined a model "User" which has a belongsToMany relation with a model "Location". I then have a model "Asset" which also has a belongsToMany relation with "Location". When I have an instance of a User I would like to fetch all Assets that are associated with Locations that the User is associated with.
I tried the following which doesn't seem to work...
user.getLocations().then(function(userLocations) { return Asset.findAll({ where: { "Locations" : { $any : userLocations } }) })
Could anyone offer any suggestions?
Try this query:
User.findById(user_id, {
include: [{
model: Location,
required: true
}]
}).then(user => Asset.findAll({
where: {
user_id: user.id,
location_id: {
$in: user.locations.map(location => location.id)
}
}
})).then(assets => {
// The rest of your logic here...
});
This was the final result...
User.findById(user_id, {
include: [{
model: Location,
as: 'Locations', // Was needed since the original relation was defined with 'as'
required: true
}]
}).then(user => Asset.findAll({
include: [{
model: Location,
as: 'Locations',
where: {
id: {
$in: user.Locations.map(location => location.id)
}
}
}]
})).then(assets => {
// The rest of your logic here...
});