I am trying to increment view field by one always when it hit this api but does not work
error : Posts validation failed: view: Cast to number failed for value
view: {
type: Number,
default: 0
},
async request(req, res) => {
const post = await PostsModel.findOne({ _id: post_id });
post.view = { $inc: { view: 1 } };
await post.save();
}
In your way, you need to do post.view = post.view + 1 instead of post.view = { $inc: { view: 1 } }; because it will set the view field to be the object { $inc: { view: 1 } }.
Or if you want to use $inc, you need to make an update operation. Something like:
await PostsModel.findOneAndUpdate({ _id: post_id }, { $inc: { view: 1 } });
Related
Is it possible, using mongoose middleware, to increment two fields one with a condition and the other without? In this case i want to increment "stats.ratings" by one, if the user inserts an input greater than 0, else increment zero.
"stats.answered" always increments one
See code below
module.exports.updateStats = function (req, res) {
var rating = parseInt(req.body.rating, 10);
var wasRated;
if (rating > 0) {
wasRated = true;
} else wasRated = false
Collection.findOneAndUpdate({
_id: req.body._id
}, {
$cond: {
if: wasRated,
then: {
$inc: {
"stats.answered": 1,
"stats.ratings": 1
}
},
else: {
$inc: {
"stats.answered": 1,
"stats.ratings": 0
}
}
}
},
function (err, doc) {
if (err)
throw err;
res.status(200);
})
}
What you can do is this:
// define the default case
var update = {
$inc: {
"stats.answered": 1
}
};
if(parseInt(req.body.rating, 10) > 0) {
// override default in some cases
update = {
$inc: {
"stats.answered": 1,
"stats.ratings": 1
}
}
}
and then
Collection.findOneAndUpdate({
_id: req.body._id
}, update,
function (err, doc) {
if (err)
throw err;
res.status(200);
})
}
Building cart on website and when product is added i want to first check if it is already in cart, if yes increment quantity by 1, if not add it. Cart is an array of objects and i want to pass index of object that contains added product to increment function but can't figure out how to do so.
async function add(product, userId) {
const user = await User.findById(userId);
const product = isProductInCart(product, user.cart); // returns true and index in cart if found
if (product.found === true) {
await User.findOneAndUpdate(
{ _id: userId },
{ $inc: { cart[product.index].quantity : 1 }} // not working
);
} else {
await User.findOneAndUpdate({ _id: userId }, { $push: { cart: product } });
}
}
function isProductInCart(product, cart) {
let productFound = { found: false, index: -1 };
for (let i = 0; i < cart.length; i++)
if (cart[i].name === product.name) {
productFound.found = true;
productFound.index = i;
break;
}
return productFound;
}
It looks like your code can be simplified if you consider using the $ positional operator:
let userWithCart = User.findOneAndUpdate(
{ _id: user, 'cart.name': product.name },
{ $inc: { 'cart.$.quantity' : 1 }}
)
if(!userWithCart ){
await User.findOneAndUpdate({ _id: userId }, { $push: { cart: product } });
}
First findOneAndUpdate will return no value when there's no corresponding cart.name (and you need to $push it). Otherwise MongoDB will automatically match the cart you want to update based on cart.name condition and increment the quantity subfield.
EDIT:
If you still need to proceed the way you've started you just need to evaluate the path in JavaScript:
{ $inc: { [`cart.${product.index}.quantity`] : 1 }}
I need to build a MongoDB query by pushing a new language if it does not exist in the array already. But if it exists I get an error this '$push' is empty. It is correct.
My question is how to build the query adding $push only when it is necessary?
let pushNewLanguage = {};
if (!profile.languages || (profile.languages && !profile.languages.find(l => l === languageId))) {
pushNewLanguage = { languages: languageId };
}
const profileUpdate = await
Profiles.rawCollection().update(
{ userId: this.userId },
{
$inc: { countPublishedPoems: 1 },
$push: pushNewLanguage
}
);
Remove the conditional logic and use $addtoSet instead of $push.
$addToSet will only add the item if it doesn’t exist already.
const profileUpdate = await
Profiles.rawCollection().update(
{ userId: this.userId },
{
$inc: { countPublishedPoems: 1 },
$addToSet: { languages: languageId }
}
);
Since you are writing Javascript, you can create a "base" update object, and then add the $push property if you need:
const update = {
$inc: { countPublishedPoems: 1 }
}
if (!profile.languages || (profile.languages && !profile.languages.find(l => l === languageId))) {
update["$push"] = { languages: languageId };
}
const profileUpdate = await
Profiles.rawCollection().update(
{ userId: this.userId },
update
);
I have this Schema:
const guestSchema = new Schema({
id: String,
cart: [
{
product: {
type: mongoose.Schema.ObjectId,
ref: "products"
},
quantity: Number
}
]
});
I have this query:
Guest.findOneAndUpdate(
{ id: req.sessionID },
{
$cond: [
{ "cart.product": { $ne: req.body.itemID } },
{ $push: { "cart": { product: req.body.itemID, quantity: 1 } } },
{ $inc: { "cart.quantity": 1 } }
]
},
{ upsert: true, new: true }
).exec(function(err, docs) {
err ? console.log(err) : res.send(docs);
});
Basically, what I'm trying to do is update based on a condition. I tried using $cond, but found out that operator isn't used for querys like I'm doing.
Based on this:
{ $cond: [ <boolean-expression>, <true-case>, <false-case> ] }
I want something similar to the functionality of this operator for my query.
Let's break down my condition:
For my boolean expression: I want to check if req.body.itemID is $ne to any of the values in my cart
If true then: $push the itemID and quantity into the cart
Else (then item already exists): $inc the quantity by 1
Question: How would achieve this result? Do I need to make two seperate querys? I'm trying to avoid doing that if possible
I went through all their Update Field Operators, and there's probably no way to do this in the way I want.
I wonder why there is no $cond for update operators. Nonetheless, I have the solution to what I wanted the functionality accomplish. Just not in the elegant fashion that I would like it.
Guest.findOneAndUpdate(
{ id: req.sessionID },
{ id: req.sessionID }, //This is here in case need to upsert new guest
{ upsert: true, new: true }
).exec(function(err, docs) {
if (err) {
console.log(err);
} else {
//Find the index of the item in my cart
//Returns (-1) if not found
const item = doc.cart.findIndex(
item => item.product == req.body.itemID
);
if (item !== -1) {
//Item found, so increment quantity by 1
doc.cart[item].quantity += 1;
} else {
//Item not found, so push into cart array
doc.cart.push({ product: req.body.itemID, quantity: 1 });
}
doc.save();
}
});
This type of logic does not belong within the database query. It should happen in the application layer. MongoDB is also very fast at retrieving and updating single records with an index so that should not be a concern.
Please try doing something like this:
try {
const guest = await Guest.findOne().where({
id: req.sessionID
}).exec();
// your cond logic, and update the object
await guest.save();
res.status(200).json(guest);
} catch (error) {
handleError(res, error.message);
}
I have a meteor game
On the server i have a timer that calls meteor method moveFish.
Meteor.startup(() => {
Meteor.setInterval(function(){
Meteor.call("moveFish")
}, 40);
});
That method selects all fishes are alive and make them move
Meteor.methods({
moveFish: function(id, speed) {
Meteor.users.update( { "fish.alive": true }, { $inc: { "fish.positionX": 2 } } )
}
})
How do I move fish using this.fish.speed instead value 2
Meteor.users.update( { "fish.alive": true }, { $inc: { "fish.positionX": 2 } } )
*Notice that doesn't work
Meteor.users.update( { "fish.alive": true }, { $inc: { "fish.positionX": "fish.speed" } } )
That's works
Meteor.users.find().map( function(user) { x = user.fish.speed Meteor.users.update(user, {$inc: {"fish.positionX": x} }) })
Unfortunately document can't use the reference to itself on update operation.
You need to find it first and iterate over all documents manually in this case:
Meteor.users.findAll({ "fish.alive": true }).fetch().forEach(function(fish) {
fish.positionX += fish.speed;
fish.save();
});