I'm trying to use some nested arrays in mongoDB but after several hours fighting with the mongo docs and several other SO questions. I'm thinking I might be doing something terribly wrong. The code below is supposed to update the confirms array in the confirms array but it won't ever do anything but add new entries. Any help would be appreciated.
Events.update({_id: eventId, "confirms.person": personId}, {
$set: {
"confirms.$.person": personId,
"confirms.$.confirmed": isConfirmed,
"confirms.$.timestamp": new Date()
}
});
And here is a sample of the data I'm trying to operate on, it is currently WRONG because a personId should be unique.
{
"_id": "RnE4PaPSZ9FC9MAAQ",
"eventTitle": "Epic lan PARTY!!!!!",
"eventDate": "31/07/2015",
"confirms": [{
"person": "jjoqekYYaA6n8nYvs",
"confirmed": true,
"timestamp": ISODate("2015-07-25T17:15:28.212Z")
}, {
"person": "jjoqekYYaA6n8nYvs",
"confirmed": true,
"timestamp": ISODate("2015-07-25T17:16:50.485Z")
}
}]
}
Just in case it might turn out to be relevant, i'm working in meteor js.
To update the element of an array which is the variable of a Collection item you could do this:
Get the array:
var arr = Events.findOne({_id: eventId}).confirms;
Do your operation
Update old array with modified array:
Events.update({_id: eventId}, {$set: {confirms: arr}});
In case of problems with step 2: you could iterate through the array checking if this.person === personId then set this.confirmed = isConfirmed & this.timestamp = new Date.
There might be ways of operating on arrays within Mongo but this one works for sure.
Related
I have a mongo collection where a field is supposed to point to another document's id in the same collection, but instead it is pointing to its "number". I need to perform an update on them but I'm having some problems on forming the query. Could you help me?
The structure of the document is like this:
{
"_id": "269410e2-cebf-40f1-a81f-fdce34185cdc",
"number": 1471,
"alternativeLocationId": "9871",
"locationType": "DUMMY"
},
{
"_id": "2945b24a-b82f-45a9-ad06-a884379b5597",
"number": 9871,
"locationType": "MAIN"
}
So as asked, I'd need to make document with number 1471 "alternativeLocationId" to be "2945b24a-b82f-45a9-ad06-a884379b5597" instead of 9871 (Note that the referenced documents are not locationType "DUMMY" nor have this alternativeLocationId field).
The query I've done so far goes like this, but when executed its not doing any changes:
db.location.find({alternativeLocationId: {$exists:true}}).forEach(
function (loc) {
var correctLocation = db.location.findOne({number: loc.alternativeLocationId});
db.location.update(
{_id: loc._id},
{$set: {alternativeLocationId: correctLocation._id} }
);
}
);
As mentioned by user20042973 the issue was the type mismatch between alternativeLocationId and locationNumber, after converting the value to int when looking for it, it works perfectly.
I have schema data like below
{
id:'5d60fd38f6999a7792c940a4'
name:'test',
department:[
{
d_name:'Rd',
_id:'5d61092b1f234c11348eb831'
equipements:[
{
id:'5d637abd7ddd183263fa4ebc'
e_name:'first'
},
]
}
]
}
and I'm try to update the equipments by following way
College.updateOne(
{
_id: productObjectID,
'department._id': variantObjectId
},
{ $set: data }
);
but unfortunately this query is not update my equipment data .
can let me know what is right way to update. thanks
You need to search with the equipements.id in order to udpate the name
This would work
College.updateOne({
_id: productObjectID,
"department._id": variantObjectId,
"department.equipements.id": equipementId
},{ "$set": {"department.equipements.$.name": "updatedName"} });
I assume you're trying to achieve the below:
db.dummyTest.updateOne({ "_id" : ObjectId("5d63a1791b761bfc0420e590"),
"department._id": "5d61092b1f234c11348eb831",
"department.equipements._id": "5d637abd7ddd183263fa4ebc" },
{ $set: { "department.$.equipements.0.e_name.0": "Update to last" }})
MongoDB's support for updating nested arrays is poor. So you're best off avoiding their use if you need to update the data frequently
Option 1: Make department its own collection (make department, as sub document instead of array)
Option 2: Achieve it through program
I'm working on a Meteor application and I have data for a weekly timetable of the format -
events:
event:
day: "Monday"
time: "9am"
location: "A"
event:
day: "Monday"
time: "10am"
location: "B"
There are numerous entries for each day. Can I run a query that will return an object of the format -
day: "Monday"
events:
event:
time: "9am"
location: "A"
event:
time: "10am"
location: "B"
I could store the object in the second format but prefer the first for ease of deleting and updating individual events.
I also want to return them ordered by day of week if there's a nice way to do that.
Several options:
You can use an aggregation command but be warned, you will loose reactivity: it means that except when you reload your template, you will not get external updates. You would also need to use a package to add the aggregation command to Meteor in order to achieve that.
My personal favorite: you don't need to aggregate (and loose reactivity) to achieve your data transformation. You can use a simple Collection.find() query and extend/reduce/modify it using a clever mix of cursor.Observe() and conditional modifications. Have a look at this answer, it did the trick for me (I needed a sum with black listing of some fields, but you can easily adapt it to your group/sorting case) : https://stackoverflow.com/a/30813050/3793161. Comment if you need more details on this
If you plan to have several servers, be warned that each server will have to observe so it may lead to an unnecessary load. So my third solution is either use collection hooks or methods to update an additional field containing every event for each day/user (whatever you need).See #David Weldon answer about that here: https://stackoverflow.com/a/31190896/3793161. In you case, it would probably mean to re-think your database structure to fit your needs (i.e. adding more fields so you ca update them on insert.
EDIT Here are some thoughts on your comment:
If you stick to what you described in the question, you would need seven documents, one per day, with an events field where you put all the events. My second solution is good if you need to rework a collection structure before sending it. However, in your case, you just need an object week with 7 sub-objects matching the days of the week.
I advise you to possible approaches:
use the aggregation in a method, as described by #chridam. Be warned that you will not be able to directly get a sorted array, as stated in mongo $group documentation
$group does not order its output documents
So you need to sort them (by day and by hour within each day) using, for example _.sortBy() before you return your method result. By the way, if you want to know what is going on in your method call, clientside, here is how you should write the call:
Meteor.call("getGroupedDailyEvents", userId, function(error, result){
if(error){
console.log("error", error);
}
if(result){
//do whatever you need
}
});
Make the data sorting client-side. You are looking for an overkill solution because, afaik, you don't need to filter any data to keep it from the user, and you are going to send the data anyway (just with another structure). This is much easier to make a simple helper in your template like this:
Template.displaySchedule.helpers({
"monday_events": function() {
return _.sortBy (events.find({day:"Monday"}).fetch(), "time")
},
//add other days
);
It assumes the format of your time field is sortable this way. If not, you just need to create a function to sort them accordingly to their formats or change the original format into something better suited.
The rest (HTML) would just be to iterate on Monday events using a {{#each monday_events}}
To achieve the desired result, use the aggregation framework where the $group pipeline operator groups all the input documents and apply the accumulator expression $push to the group to get the events array.
Your pipeline would look like this:
var Events = new Mongo.Collection('events');
var pipeline = [
{
"$group": {
"_id": "$day",
"events": {
"$push": {
"time": "$time"
"location": "$location"
}
}
}
},
{
"$project": {
"_id": 0, "day": "$_id", "events": 1
}
}
];
var result = Events.aggregate(pipeline);
console.log(result)
You can add the meteorhacks:aggregate package to implement the aggregation in Meteor:
Add to your app with
meteor add meteorhacks:aggregate
Since this package exposes .aggregate method on Mongo.Collection instances, you can define a method that gets the aggregated result array. For example
if (Meteor.isServer) {
var Events = new Mongo.Collection('events');
Meteor.methods({
getGroupedDailyEvents: function () {
var pipeline = [
{
"$group": {
"_id": "$day",
"events": {
"$push": {
"time": "$time"
"location": "$location"
}
}
}
},
{
"$project": {
"_id": 0, "day": "$_id", "events": 1
}
}
];
var result = Events.aggregate(pipeline);
return result;
}
});
}
if (Meteor.isClient) {
Meteor.call('getGroupedDailyEvents', logResult);
function logResult(err, res) {
console.log("Result: ", res)
}
}
I understand Manual referencing being, one document containing the reference to another.
As in the MongoDB's documentation:
original_id = ObjectId()
db.places.insert({
"_id": original_id,
"name": "Broadway Center",
"url": "bc.example.net"
})
db.people.insert({
"name": "Erin",
"places_id": original_id,
"url": "bc.example.net/Erin"
})
I am able to use a find on the places to get a certain name.
db.places.find({name : "Broadway Center"});
This will give the id. And then my application can use this ID to query the people to see who live here?
But, If i dont have a application. How would I go about doing this solely in a mongo shell? I was thinking about using find, and then iterating over the cursor using a forEach? But this seems a bit hacky.
Any suggestions?
You don't need to loop through using the cursor from find(), just use findOne() because a single document is returned with this method and you have access to the document directly (no need to apply cursor methods to the result). In mongo shell you can do this:
var result = db.places.findOne({name : "Broadway Center"});
if (result) {
var place_id = result._id;
var peopleArray = db.people.find({ "places_id": place_id }).toArray();
if (peopleArray.length > 0) { printjson (peopleArray[0]); }
}
I have different types of data that would be difficult to model and scale with a relational database (e.g., a product type)
I'm interested in using Mongodb to solve this problem.
I am referencing the documentation at mongodb's website:
http://docs.mongodb.org/manual/tutorial/model-referenced-one-to-many-relationships-between-documents/
For the data type that I am storing, I need to also maintain a relational list of id's where this particular product is available (e.g., store location id's).
In their example regarding "one-to-many relationships with embedded documents", they have the following:
{
name: "O'Reilly Media",
founded: 1980,
location: "CA",
books: [12346789, 234567890, ...]
}
I am currently importing the data with a spreadsheet, and want to use a batchInsert.
To avoid duplicates, I assume that:
1) I need to do an ensure index on the ID, and ignore errors on the insert?
2) Do I then need to loop through all the ID's to insert a new related ID to the books?
Your question could possibly be defined a little better, but let's consider the case that you have rows in a spreadsheet or other source that are all de-normalized in some way. So in a JSON representation the rows would be something like this:
{
"publisher": "O'Reilly Media",
"founded": 1980,
"location": "CA",
"book": 12346789
},
{
"publisher": "O'Reilly Media",
"founded": 1980,
"location": "CA",
"book": 234567890
}
So in order to get those sort of row results into the structure you wanted, one way to do this would be using the "upsert" functionality of the .update() method:
So assuming you have some way of looping the input values and they are identified with some structure then an analog to this would be something like:
books.forEach(function(book) {
db.publishers.update(
{
"name": book.publisher
},
{
"$setOnInsert": {
"founded": book.founded,
"location": book.location,
},
"$addToSet": { "books": book.book }
},
{ "upsert": true }
);
})
This essentially simplified the code so that MongoDB is doing all of the data collection work for you. So where the "name" of the publisher is considered to be unique, what the statement does is first search for a document in the collection that matches the query condition given, as the "name".
In the case where that document is not found, then a new document is inserted. So either the database or driver will take care of creating the new _id value for this document and your "condition" is also automatically inserted to the new document since it was an implied value that should exist.
The usage of the $setOnInsert operator is to say that those fields will only be set when a new document is created. The final part uses $addToSet in order to "push" the book values that have not already been found into the "books" array (or set).
The reason for the separation is for when a document is actually found to exist with the specified "publisher" name. In this case, all of the fields under the $setOnInsert will be ignored as they should already be in the document. So only the $addToSet operation is processed and sent to the server in order to add the new entry to the "books" array (set) and where it does not already exist.
So that would be simplified logic compared to aggregating the new records in code before sending a new insert operation. However it is not very "batch" like as you are still performing some operation to the server for each row.
This is fixed in MongoDB version 2.6 and above as there is now the ability to do "batch" updates. So with a similar analog:
var batch = [];
books.forEach(function(book) {
batch.push({
"q": { "name": book.publisher },
"u": {
"$setOnInsert": {
"founded": book.founded,
"location": book.location,
},
"$addToSet": { "books": book.book }
},
"upsert": true
});
if ( ( batch.length % 500 ) == 0 ) {
db.runCommand( "update", "updates": batch );
batch = [];
}
});
db.runCommand( "update", "updates": batch );
So what is doing in setting up all of the constructed update statements into a single call to the server with a sensible size of operations sent in the batch, in this case once every 500 items processed. The actual limit is the BSON document maximum of 16MB so this can be altered appropriate to your data.
If your MongoDB version is lower than 2.6 then you either use the first form or do something similar to the second form using the existing batch insert functionality. But if you choose to insert then you need to do all the pre-aggregation work within your code.
All of the methods are of course supported with the PHP driver, so it is just a matter of adapting this to your actual code and which course you want to take.