I've a node.js api in which user sends the required fields as an array to be fetched from the mongodb database. I need to find the data of that fields using Find query. I've written forEach statement to loop through that array and got the array elements. But when I try to get the results by inserting the array elements in the query, it doesn't giving the required results. Could any one please help me in resolving the issue by seeing the code below?
templateLevelGraphData: async function(tid,payload){
let err, templateData, respData = [], test, currentValue;
[err,templateData] = await to(Template.findById(tid));
var templateId = templateData.templateId;
payload.variables.forEach(async data=>{
console.log(data); //data has the array elements like variables=["humidity"]
[err, currentValue] = await to(mongoose.connection.db.collection(templateId).find({},{data:1}).sort({"entryDayTime":-1}).limit(1).toArray());
console.log(currentValue);
});
return "success";
}
The expected output is,
[ { humidity: 36 } ]
But I'm getting only _id like,
[ { _id: 5dce3a2df89ab63ee4d95495 } ]
I think data is not applying in the query. But I'm printing the data in the console where it's giving the correct results by displaying the array elements like, humidity. What I need to do to make it work?
When you are passing {data: 1} you are passing an array where is expecting name of column.
You have to create an object where the keys are going to be the elements of the array and set them to 1.
const projection = data.reduce((a,b) => (a[b]=1, a), {});
[...] .find({}, projection) [...]
Actually I got the solution.
for(let i=0;i<payload.variables.length;i++){
var test = '{"'+ payload.variables[i] +'":1,"_id":0}';
var query = JSON.parse(test);
[err, currentValue] = await to(mongoose.connection.db.collection(templateId).find({"deviceId":deviceId},query).sort({"entryDayTime":-1}).limit(1).toArray());
console.log(currentValue); //It's giving the solution
}
Related
Hi I tried to update the element at a particular index in an array but I'm not able to update it. It is updating the entire array. Not able to figure out how to update any particular index. Also tried
{$set:{"Data.1:req.body}}
this is updating at 1st index but I don't want to hardcode the index value. It should take from frontend. Let say I have a schema in which I have Data who's type is array and default value is as shown below or anything in the same format.
Data: {
type: Array,
Default: ["0","1","0"]
}
Whenever I'll create a user then Data field will contain these default values, But now I want to update the value at any index (coming from frontend) of Data array of any user created.
I tried findByIdAndUpdate method but I don't know what to pass in set property. If I'm passing this {$set: req.body} and In postman I'm giving any value of Data then obviously it is updating Data array but I want to update value at any index which I'm passing from frontend, let say the index I'm passing is 2 then it should update the value of array at index 2, similarly I can pass any index from frontend how should I do that. What changes I have to make in {$set : } Thanks in advance.
Waiting for any help or suggestions. Thanks
It appears that you can solve this in backend logic if you are passing the index from the frontend.
You can dynamically specify the index, based on the input from the frontend, before you send a query.
const updateUserData = async (req, res) => {
const { index, user_id, new_value } = req.body;
try {
const update = {};
update[`Data.${index}`] = new_value;
const data = await Users.updateOne(
{ _id: user_id },
{ $set: update }
);
return res.status(200).json({ success: true });
} catch (error) {
return res.status(500).json({ success: false });
}
};
I'm currently writing a small API for a cooking app. I have a Recipe model and would like to implement sorting by columns based on the req Parameter given.
I'd like to sort by whatever is passed in the api call. the select parameter works perfectly fine, I can select the columns to be displayed but when I try to sort anything (let's say by rating) the return does sort but I'm not sure what it does sort by.
The code i'm using:
query = Recipe.find(JSON.parse(queryStr));
if(req.query.select){
const fields = req.query.select.split(',').join(' ');
query = query.select(fields);
}
if(req.query.sort){
const sortBy = req.query.sort.split(',').join(' ');
query = query.sort({ sortBy: 1 });
} else {
query = query.sort({ _id: -1 });
}
The result, when no sorting is set: https://pastebin.com/rPLv8n5s
vs. the result when I pass &sort=rating: https://pastebin.com/7eYwAvQf
also, when sorting my name the result is also mixed up.
You are not using the value of sortBy but the string "sortBy". You will need to create an object that has the rating as an object key.
You need the sorting object to look like this.
{
rating: 1
}
You can use something like this so it will be dynamic.
if(req.query.sort){
const sortByKey = req.query.sort.split(',').join(' ');
const sortByObj = {};
sortByObj[sortByKey] = 1; // <-- using sortBy as the key
query = query.sort(sortByObj);
} else {
query = query.sort({ _id: -1 });
}
I'm shortlisting the 2 elements from one schema and want to update in another schema. for that i used slice method to shortlist first 2 elements from an array. but am Getting
CoreMongooseArray ['element1','element2']
instead of ["element1", "element2"]
How do i remove "CoreMongooseArray" ?
connection.connectedusers.find({}, async (err, docs) => {
if(err) throw err;
var users = docs[0].connectArray;
if (docs[0] != null && users.length >= 2) {
var shortListed = users.slice(0, 2);
try {
await connection.chatschema.updateMany({}, { $push: { usersConnected: [shortListed] } }, { upsert: true });
} catch (err) {
res.status(201).json(err);
}
}
You need to add lean() to your query.
From the docs:
Documents returned from queries with the lean option enabled are plain javascript objects, not Mongoose Documents. They have no save method, getters/setters, virtuals, or other Mongoose features.
If you already got the mongoose array and like to convert to simple js array
const jsArray = mongooseArray.toObject();
https://mongoosejs.com/docs/api/array.html#mongoosearray_MongooseArray-toObject
For some reason .toObject() didn't work for me. lean() option works, but it's not suitable when you already have an object with mongoose array in it. So in case if you already have mongoose array and you want just to convert it to plain js array you can use following code:
function mongooseArrayToArray(mongooseArray) {
const array = [];
for (let i = 0; i < mongooseArray.length; i += 1) {
array.push(mongooseArray[0]);
}
return array;
};
usage:
const array = mongooseArrayToArray(mongooseArray);
If you just want to convert the CoreMongooseArray to a normal array without changing anything else:
const jsArray = [...mongooseArray];
I'm stuck in mongoose query. I've an array of ids as input, I want to search that array of ids in a database for matching elements. It returns perfect result after using $in in find query.
Now, I want that Ids from an array which is not found in the database. what is the best way to do it?
Please try to comment it.
Template.find({
_ids : [
"as6d87as67da7s8d87a87", // available in database
"as6dasd8sa9d8a9a9s8d7", // not-available in database
"6756asd5as6dsadghasd3", // available in database
]
}, function(err, result){
// Need result as "as6dasd8sa9d8a9a9s8d7", which is not matched. or in object.
// Can we do with `aggregate` query?
});
I think this makes what you want
var _ids = [
"as6d87as67da7s8d87a87",
"as6dasd8sa9d8a9a9s8d7",
"6756asd5as6dsadghasd3"
];
Template.find({
_ids : _ids
}, function(err, result){
var filteredResult = _ids.filter(currentId => !result.some(item => item._id.toString() == currentId));
});
Answer by David will work. The idea here is to compare _ids array with the _ids in the result and return the missing ones. Adding more code just for understanding purposes:
Push _id of result into a new array
Compare _ids and the new array to return missing elements
var resIDs = new Array();
for (var i = 0; i < result.length; i++) {
resIDs.push(result[i]._id.toString());
}
var resultFiltered =
_ids.filter(function (v) {
return !resIDs.includes(v.toString());
})
Using mongoose's Model.aggregate() returns an empty array.
I've essentially copied the format as seen here.
var match = {};
var project = {};
project["_id"] = 0;
project["products.totalprice"] = 1;
project["line"] = "$products.closedate";
ThisCollection.aggregate([
{$match: match},
{$project: project},
{$group: {
_id: "$line"
}}
], function(err, docs){
console.log(docs); //!! Returning []
});
My schema is essentially a name and _id field with a nested array of products with totalprice, closedate and some other fields.
There are most certainly a plethora of entries (some 130,000 records). Can anyone spot an issue with this?
I have created this dummy data to represent a skeleton of your schema:
db.data.save({name:"a",products:{totalprice:1,closedate:1}})
db.data.save({name:"b",products:{totalprice:2,closedate:2}})
This query does return two records and is identical to yours when inserting the JSON string for the JavaScript variable project
ThisCollection.aggregate([{$match:{}},{$project:{"_id":0,"products.totalprice":1,line:"$products.closedate"}},{$group:{_id:"$line"}}])