I have the following structure in mongodb document
Note : Mongodb Version 3.4
{
"_id" : "1",
"settings" : {
"shapes":[
{
"shape":"square",
"color":"blue"
},
{
"shape":"circle",
"color":"red"
},
{
"shape":"round",
"color":"black"
}
]
}
}
Here i want to update the shape square & round, because value array i am having this two shapes.below code i tried but it is not working my expected.
my code
var value= [
{
"shape":"square",
"color":"yellow"
},
{
"shape":"round",
"color":"blue"
}
]
db.Colleges.update({"_id" : "1"},{
$set : {
"settings.shapes": value
}
},{multi:true})
After update i need this output
{
"_id" : "1",
"shapes":[
{
"shape":"square",
"color":"yellow"
},
{
"shape":"circle",
"color":"red"
},
{
"shape":"round",
"color":"blue"
}
]
}
I am getting output
{
"_id" : "1",
"shapes":[
{
"shape":"square",
"color":"yellow"
},
{
"shape":"round",
"color":"blue"
}
]
}
actually here shape circle and color red is getting disappear, kindly any one update my code.
var value array not a static array, it is dynamic based on objects we to update the document.
Related
I wrote a mongo shell script to insert in a new collection the result of an aggregation; my problem is that the null values from the source collection are replaced by zero; the aggregation part is:
db.getCollection("unhcr_pop_concern_flat").aggregate(
[
{
"$group" : {
"_id" : {
"country" : "$country",
"time" : "$time",
"origin": "$origin"
},
"value_fields": {
"$addToSet": {
k: "$type",
v: {$ifNull: ["$value", null]}
}
}
}
},
{ $addFields: { value_fields: { $arrayToObject: "$value_fields" } } }
],
{
"allowDiskUse" : true
}
Where is the problem? I have also used the $ifnull operator.
The query is working correctly; there was a problem in the source collections where data were changed by others!
I am working on an express js application where I need to update a nested array.
1) Schema :
//Creating a mongoose schema
var userSchema = mongoose.Schema({
_id: {type: String, required:true},
name: String,
sensors: [{
sensor_name: {type: String, required:true},
measurements: [{time: String}]
}] });
2)
Here is the code snippet and explanation is below:
router.route('/sensors_update/:_id/:sensor_name/')
.post(function (req, res) {
User.findOneAndUpdate({_id:req.body._id}, {$push: {"sensors" :
{"sensor_name" : req.body.sensor_name , "measurements.0.time": req.body.time } } },
{new:true},function(err, newSensor) {
if (err)
res.send(err);
res.send(newSensor)
}); });
I am able to successfully update a value to the measurements array using the findOneAndUpdate with push technique but I'm failing when I try to add multiple measurements to the sensors array.
Here is current json I get if I get when I post a second measurement to the sensors array :
{
"_id": "Manasa",
"name": "Manasa Sub",
"__v": 0,
"sensors": [
{
"sensor_name": "ras",
"_id": "57da0a4bf3884d1fb2234c74",
"measurements": [
{
"time": "8:00"
}
]
},
{
"sensor_name": "ras",
"_id": "57da0a68f3884d1fb2234c75",
"measurements": [
{
"time": "9:00"
}
]
}]}
But the right format I want is posting multiple measurements with the sensors array like this :
Right JSON format would be :
{
"_id" : "Manasa",
"name" : "Manasa Sub",
"sensors" : [
{
"sensor_name" : "ras",
"_id" : ObjectId("57da0a4bf3884d1fb2234c74"),
"measurements" : [
{
"time" : "8:00"
}
],
"measurements" : [
{
"time" : "9:00"
}
]
}],
"__v" : 0 }
Please suggest some ideas regarding this. Thanks in advance.
You might want to rethink your data model. As it is currently, you cannot accomplish what you want. The sensors field refers to an array. In the ideal document format that you have provided, you have a single object inside that array. Then inside that object, you have two fields with the exact same key. In a JSON object, or mongo document in this context, you can't have duplicate keys within the same object.
It's not clear exactly what you're looking for here, but perhaps it would be best to go for something like this:
{
"_id" : "Manasa",
"name" : "Manasa Sub",
"sensors" : [
{
"sensor_name" : "ras",
"_id" : ObjectId("57da0a4bf3884d1fb2234c74"),
"measurements" : [
{
"time" : "8:00"
},
{
"time" : "9:00"
}
]
},
{
// next sensor in the sensors array with similar format
"_id": "",
"name": "",
"measurements": []
}],
}
If this is what you want, then you can try this:
User.findOneAndUpdate(
{ _id:req.body._id "sensors.sensor_name": req.body.sensor_name },
{ $push: { "sensors.0.measurements": { "time": req.body.time } } }
);
And as a side note, if you're only ever going to store a single string in each object in the measurements array, you might want to just store the actual values instead of the whole object { time: "value" }. You might find the data easier to handle this way.
Instead of hardcoding the index of the array it is possible to use identifier and positional operator $.
Example:
User.findOneAndUpdate(
{ _id: "Manasa" },
{ $push: { "sensors.$[outer].measurements": { "time": req.body.time } } }
{ "arrayFilters:" [{"outer._id": ObjectId("57da0a4bf3884d1fb2234c74")}]
);
You may notice than instead of getting a first element of the array I specified which element of the sensors array I would like to update by providing its ObjectId.
Note that arrayFilters are passed as the third argument to the update query as an option.
You could now make "outer._id" dynamic by passing the ObjectId of the sensor like so: {"outer._id": req.body.sensorId}
In general, with the use of identifier, you can get to even deeper nested array elements by following the same procedure and adding more filters.
If there was a third level nesting you could then do something like:
User.findOneAndUpdate(
{ _id: "Manasa" },
{ $push: { "sensors.$[outer].measurements.$[inner].example": { "time": req.body.time } } }
{ "arrayFilters:" [{"outer._id": ObjectId("57da0a4bf3884d1fb2234c74"), {"inner._id": ObjectId("57da0a4bf3884d1fb2234c74"}}]
);
You can find more details here in the answer written by Neil Lunn.
refer ::: positional-all
--- conditions :: { other_conditions, 'array1.array2.field_to_be_checked': 'value' }
--- updateData ::: { $push : { 'array1.$[].array2.$[].array3' : 'value_to_be_pushed' } }
Firebase structure:
{
"config" : [
{
"config1" : {
"hideimage" : true
}
},
{
"config2" : {
"hideimage" : false
}
}
]
}
Database rules:
"config": {
".indexOn": ["hideimage"]
}
I'm trying to retrieve all config items that have hideimage attribute set to true using:
admin.database().ref('config').orderByChild("hideimage").equalTo(true).once('value', result => {});
The expected result should be:
[{
"config1" : {
"hideimage" : true
}
}]
but I'm retrieving a null response without getting any error.
Your data structure contains two nested levels:
you have an array
inside the first array element, you have config1 and config2
You can see this if you look at the Firebase console, where your data will show like:
{
"config" : {
"0": {
"config1" : {
"hideimage" : true
}
},
{
"config2" : {
"hideimage" : false
}
}
}
}
Firebase can only query nodes in a flat list, not a tree. So with your current data structure it can only find the node with hideimage=true under /config/0, not under all /config children.
Since you're already naming your config1 and config2 uniquely, I think the array may be a mistake, and you're really looking for:
{
"config": {
"config1" : {
"hideimage" : true
},
"config2" : {
"hideimage" : false
}
}
}
With this data structure your query will work.
I need get value of field without using $unwind
because $unwind and $group takes much longer time.
My document (looks like):
{
"_id" : ObjectId("512e28984815cbfcb21646a7"),
"providers" : [
{
"list" : [
{
"code" : "ATT",
"descr" : "Attending"
}
],
"Name" : "John Doe",
"prvdId" : "1"
},
{
"list" : [
{
"code" : "RFR",
"descr" : "Referring"
},
{
"code" : "TRT",
"descr" : "Treating"
}
],
"Name" : "Smith William",
"prvdId" : "2"
}
]
}
cond is if "code" : "TRT", than get "prvdId"
Expected result is
{"prvdId" : "2"}
Use $filter with $in to look for a match in nested array followed by $let with $arrayElemAt to output prvdId in 3.4.
db.col.aggregate([
{"$match":{"providers.list.code":"TRT"}},
{"$project":{
"_id":0,
"prvdId":{
"$let":{
"vars":{
"providersl":{
"$filter":{
"input":"$providers",
"as":"providerf",
"cond":{"$in":["TRT","$$providerf.list.code"]}
}
}
},
"in":{"$arrayElemAt":["$$providersl.prvdId",0]}
}
}
}}
])
According to above mentioned description as a solution expected result can be obtained by using $elemMatch operator used to search an array element into find operation.
db.collection.find({
providers: {
$elemMatch: {
list: {
$elemMatch: {
code: "TRT"
}
}
}
}
}, {
'providers.$.prvdId': 1
})
I am trying to implement a function that collects unread messages from an articles collection. Each article in the collection has a "discussions" entry with discussion comment subdocuments. An example of such a subdocument is:
{
"id": NumberLong(7534),
"user": DBRef("users", ObjectId("...")),
"dt_create": ISODate("2015-01-26T00:10:44Z"),
"content": "The discussion comment content"
}
The parent document has the following (partial) structure:
{
model: {
id: 17676,
title: "Article title",
author: DBRef("users", ObjectId(...)),
// a bunch of other fields here
},
statistics: {
// Statistics will be stored here (pageviews, etc)
},
discussions: [
// Array of discussion subdocuments, like the one above
]
}
Each user also has a last_viewed entry which is a document, an example is as follows:
{
"17676" : "2015-01-10T00:00:00.000Z",
"18038" : "2015-01-10T00:00:00.000Z",
"18242" : "2015-01-20T00:00:00.000Z",
"18325" : "2015-01-20T00:00:00.000Z"
}
This means that the user has looked at discussion comments for the last time on January 10th 2015 for articles with IDs 17676 and 18038, and on January 20th 2015 for articles with IDs 18242 and 18325.
So I want to collect discussion entries from the article documents, and for article with ID 17676, I want to collect the discussion entries that were created after 2015-01-10, and for article with ID 18242, I want to show the discussion entries created after 2015-01-20.
UPDATED
Based on Neil Lunn's reply, the function I have created so far is:
function getUnreadDiscussions(userid) {
user = db.users.findOne({ 'model.id': userid });
last_viewed = [];
for(var i in user.last_viewed) {
last_viewed.push({
'id': parseInt(i),
'dt': user.last_viewed[i]
});
}
result = db.articles.aggregate([
// For now, collect just articles the user has written
{ $match: { 'model.author': DBRef('users', user._id) } },
{ $unwind: '$discussions' },
{ $project: {
'model': '$model',
'discussions': '$discussions',
'last_viewed': {
'$let': {
'vars': { 'last_viewed': last_viewed },
'in': {
'$setDifference': [
{ '$map': {
'input': '$$last_viewed',
'as': 'last_viewed',
'in': {
'$cond': [
{ '$eq': [ '$$last_viewed.id', '$model.id' ] },
'$$last_viewed.dt',
false
]
}
} },
[ false ]
]
}
}
}
}
},
// To get a scalar instead of a 1-element array:
{ $unwind: '$last_viewed' },
// Match only those that were created after last_viewed
{ $match: { 'discussions.dt_create': { $gt: '$last_viewed' } } },
{ $project: {
'model.id': 1,
'model.title': 1,
'discussions': 1,
'last_viewed': 1
} }
]);
return result.toArray();
}
The whole $let thing, and the $unwind after that, transforms the data into the following partial projection (with the last $match commented out):
{
"_id" : ObjectId("54d9af1dca71d8054c8d0ee3"),
"model" : {
"id" : NumberLong(18325),
"title" : "Article title"
},
"discussions" : {
"id" : NumberLong(7543),
"user" : DBRef("users", ObjectId("54d9ae24ca71d8054c8b4567")),
"dt_create" : ISODate("2015-01-26T00:10:44Z"),
"content" : "Some comment here"
},
"last_viewed" : ISODate("2015-01-20T00:00:00Z")
},
{
"_id" : ObjectId("54d9af1dca71d8054c8d0ee3"),
"model" : {
"id" : NumberLong(18325),
"title" : "Article title"
},
"discussions" : {
"id" : NumberLong(7554),
"user" : DBRef("users", ObjectId("54d9ae24ca71d8054c8b4567")),
"dt_create" : ISODate("2015-01-26T02:03:22Z"),
"content" : "Another comment here"
},
"last_viewed" : ISODate("2015-01-20T00:00:00Z")
}
So far so good here. But the problem now is that the $match to select only the discussions created after the last_viewed date is not working. I am getting an empty array response. However, if I hard-code the date and put in $match: { 'discussions.dt_create': { $gt: ISODate("2015-01-20 00:00:00") } }, it works. But I want it to take it from last_viewed.
I found another SO thread where this issue has been resolved by using the $cmp operator.
The final part of the aggregation would be:
[
{ /* $match, $unwind, $project, $unwind as before */ },
{ $project: {
'model': 1,
'discussions': 1,
'last_viewed': 1,
'compare': {
$cmp: [ '$discussions.dt_create', '$last_viewed' ]
}
} },
{ $match: { 'compare': { $gt: 0 } } }
]
The aggregation framework is great, but it takes quite a different approach in problem-solving. Hope this helps anyone!
I'll keep the question unanswered in case anyone else has a better answer/method. If this answer has been upvoted enough times, I'll accept this one.