Mongodb Java add new array element in document - arrays

I'm using mongo 2.2.3 and the java driver. My dilemma, I have to $push a field and value into an array element, but I cant seem to figure out how to do this. A sample of my data:
"_id" : 1,
"scores" : [
{
"type" : "english",
"score" : 78.97979
},
{
"type" : "spanish",
"score" : 6.99
}
]
I want to push one array attribute ("grade" : "A") in document where type = english.
after push document look like this :
"_id" : 1,
"scores" : [
{
"type" : "english",
"score" : 78.97979,
"grade" : "A"
},
{
"type" : "spanish",
"score" : 6.99
}
]
I tried using shell :
db.Sample.update({"scores.type" : "english"},{"$push" : {"scores": {"grade":"A"}}})
But this is not adding attribute on specific position.

Try this update with Set and reference:
db.Sample.update({"scores.type" : "english"},{"$set" : {"scores.$.grade":"A"}})

Related

How to group records based on array elements using MongoDB

I have a data collection which contains a set of records in the following format.
{
"_id" : 22,
"title" : "3D User Interfaces with Java 3D",
"isbn" : "1884777902",
"pageCount" : 520,
"publishedDate" : ISODate("2000-08-01T07:00:00Z"),
"thumbnailUrl" : "https://s3.amazonaws.com/AKIAJC5RLADLUMVRPFDQ.book-thumb-images/barrilleaux.jpg",
"longDescription" : "Description",
"status" : "PUBLISH",
"authors" : [
"Jon Barrilleaux"
],
"categories" : [
"Java",
"Computer Graphics"
]
},
{
"_id" : 23,
"title" : "Specification by Example",
"isbn" : "1617290084",
"pageCount" : 0,
"publishedDate" : ISODate("2011-06-03T07:00:00Z"),
"thumbnailUrl" : "https://s3.amazonaws.com/AKIAJC5RLADLUMVRPFDQ.book-thumb-images/adzic.jpg",
"status" : "PUBLISH",
"authors" : [
"Gojko Adzic"
],
"categories" : [
"Software Engineering"
]
}
Please note that the 'categories' is an array.
I want to count the published books for each category. I tried the following solution, but it treated the entire array as one group.
db.books.aggregate([
{
$group:{_id:"$categories", total:{$sum:1}}
}
])
Instead of so, I want to count the number of records for each individual category value inside 'categories' array.
You should first use $unwind which outputs one document for each element in the array.
db.books.aggregate([
{
$unwind : "$categories"
},
{
$group : { _id : "$categories", total: { $sum: 1 } }
}
])

Sort multiple array of objects in Mongo Aggregation

{
"_id" : 1,
"name" : "Ashwanth Madhav",
"scores" : [
{
"type" : "exam",
"score" : 45
},
{
"type" : "quiz",
"score" : 34
},
{
"type" : "work",
"score" : 99
},
{
"type" : "work",
"score" : 38
}
],
"job_type" : [
{
"type" : "full_time",
"activity" :87
},
{
"type" : "part_time",
"activity" : 78
},
{
"type" : "full_time",
"activity" : 71.76133439165544
}
]
}
When using $addToSet the sorted list is getting unsorted. So I used $push. But it leads to duplication of data.
I need to get SCORES and JOB_TYPE sorted. Now, I have done it with, Used $addToSet first, then "$unwind" score-> "$sort" -> "$group" with $push. After "$unwind" job type -> "$sort" -> "$group" it with $push.
Is there any better way? Thanks in Advance.

MongoDB - Pull multiple objects from an array

Hi I'm trying to remove multiple objects from an array that looks like this.
{
"_id" : ObjectId("5a7da1bda21d5f3e8cf005b3"),
"owner" : "1",
"group_name" : "PAASCU Board",
"group_members" : [
{
"faculty_name" : "Cheska Dela Rosa",
"faculty_number" : 2,
"_id" : ObjectId("5a7da1bda21d5f3e8cf005b5")
},
{
"faculty_name" : "Earl Sempio",
"faculty_number" : 7323,
"_id" : ObjectId("5a7da1bda21d5f3e8cf005b4")
},
{
"faculty_number" : 203,
"faculty_name" : "Sample",
"_id" : ObjectId("5a7dbf7952bd150a94d83958")
},
{
"faculty_number" : 8025,
"faculty_name" : "Sample Postman",
"_id" : ObjectId("5a7dc64a1cf5dd3d50167d53")
}
],
"__v" : 0 }
It works when I remove a single object using the $pull with this code.
db.getCollection('groups').update({_id: ObjectId("5a7da1bda21d5f3e8cf005b3")}, {$pull: {"group_members": {"faculty_number":8025}}})
But what if I want to remove multiple objects with different faculty_number? I tried using the $each method just like how I add multiple objects in the array but it doesn't work well.
Use $in operator to pass the list of faculty values to remove documents from embedded array. More here
Try
db.groups.update(
{"_id": ObjectId("5a7da1bda21d5f3e8cf005b3")},
{"$pull":{"group_members":{"faculty_number":{$in:[8025,7323]}}}}
)

Adding document to an embedded array after conditional search

Below is my code returned after the commant db.slist.findOne()
How do I add an id to the array with "iname" as "Soap"?
I need to write a query that seaches the all the "itemlist"array in the collection and if the any document inside an embedded document have "iname" as "Soap", a new row should be inserted above "iname:"Soap" as "itemID" and set an item ID myself. Can someone help me find the correct query for it?
Also this seems like a hard question, please let me know if you are finding hard to understand the question.
{
"_id" : ObjectId("5914213e9f75f9119575c1d7"),
"name" : "Athif",
"age" : 23,
"address" : {
"house" : "675/38B",
"street" : "West Hill",
"city" : "Chungam",
"pincode" : 676507
},
"itemlist" : [
{
"iname" : "Soap",
"quantity" : 2,
"price" : 10,
"rate" : 20
},
{
"iname" : "helmet",
"quantity" : 1,
"price" : 500,
"rate" : 500
},
{
"iname" : "Table",
"quantity" : 2,
"price" : 5000,
"rate" : 10000
}
]
}
For updating array elements mongodb provides positional operator $. when you apply query to find any array elements the positional operator $ holds the position of that embedded document that can be modified in update operation. So, here you go!( suppose your collection name is demo)
db.demo.update({ "itemlist.iname":"Soap" }, { $set:{"itemlist.$.itemID":"your_id"}})

Mongoose Query: Find an element inside an array

Mongoose/Mongo noob here:
My Data
Here is my simplified data, each user has his own document
{ "__v" : 1,
"_id" : ObjectId( "53440e94c02b3cae81eb0065" ),
"email" : "test#test.com",
"firstName" : "testFirstName",
"inventories" : [
{ "_id" : "active",
"tags" : [
"inventory",
"active",
"vehicles" ],
"title" : "activeInventory",
"vehicles" : [
{ "_id" : ObjectId( "53440e94c02b3cae81eb0069" ),
"tags" : [
"vehicle" ],
"details" : [
{ "_id" : ObjectId( "53440e94c02b3cae81eb0066" ),
"year" : 2007,
"transmission" : "Manual",
"price" : 1000,
"model" : "Firecar",
"mileageReading" : 50000,
"make" : "Bentley",
"interiorColor" : "blue",
"history" : "CarProof",
"exteriorColor" : "blue",
"driveTrain" : "SWD",
"description" : "test vehicle",
"cylinders" : 4,
"mileageType" : "kms" } ] } ] },
{ "title" : "soldInventory",
"_id" : "sold",
"vehicles" : [],
"tags" : [
"inventory",
"sold",
"vehicles" ] },
{ "title" : "deletedInventory",
"_id" : "deleted",
"vehicles" : [],
"tags" : [
"inventory",
"sold",
"vehicles" ] } ] }
As you can see, each user has an inventories property that is an array that contains 3 inventories (activeInventory, soldInventory and deletedInventory)
My Query
Given an user's email a a vehicle ID, i would like my query to go through find the user's activeInventory and return just the vehicle that matches the ID. Here is what I have so far:
user = api.mongodb.userModel;
ObjectId = require('mongoose').Types.ObjectId;
return user
.findOne({email : params.username})
.select('inventories')
.find({'title': 'activeInventory'})
//also tried
//.where('title')
//.equals('activeInventory')
.exec(function(err, result){
console.log(err);
console.log(result);
});
With this, result comes out as an empty array. I've also tried .find('inventories.title': 'activeInventory') which strangely returns the entire inventories array. If possible, I'd like to keep the chaining query format as I find it much more readable.
My Ideal Query
return user
.findOne({email : params.username})
.select('inventories')
.where('title')
.equals('activeInventory')
.select('vehicles')
.id(vehicleID)
.exec(cb)
Obviously it does not work but it can give you an idea what I'm trying to do.
Using the $ positional operator, you can get the results. However, if you have multiple elements in the vehicles array all of them will be returned in the result, as you can only use one positional operator in the projection and you are working with 2 arrays (one inside another).
I would suggest you take a look at the aggregation framework, as you'll get a lot more flexibility. Here's an example query for your question that runs in the shell. I'm not familiar with mongoose, but I guess this will still help you and you'd be able to translate it:
db.collection.aggregate([
// Get only the documents where "email" equals "test#test.com" -- REPLACE with params.username
{"$match" : {email : "test#test.com"}},
// Unwind the "inventories" array
{"$unwind" : "$inventories"},
// Get only elements where "inventories.title" equals "activeInventory"
{"$match" : {"inventories.title":"activeInventory"}},
// Unwind the "vehicles" array
{"$unwind" : "$inventories.vehicles"},
// Filter by vehicle ID -- REPLACE with vehicleID
{"$match" : {"inventories.vehicles._id":ObjectId("53440e94c02b3cae81eb0069")}},
// Tidy up the output
{"$project" : {_id:0, vehicle:"$inventories.vehicles"}}
])
This is the output you'll get:
{
"result" : [
{
"vehicle" : {
"_id" : ObjectId("53440e94c02b3cae81eb0069"),
"tags" : [
"vehicle"
],
"details" : [
{
"_id" : ObjectId("53440e94c02b3cae81eb0066"),
"year" : 2007,
"transmission" : "Manual",
"price" : 1000,
"model" : "Firecar",
"mileageReading" : 50000,
"make" : "Bentley",
"interiorColor" : "blue",
"history" : "CarProof",
"exteriorColor" : "blue",
"driveTrain" : "SWD",
"description" : "test vehicle",
"cylinders" : 4,
"mileageType" : "kms"
}
]
}
}
],
"ok" : 1
}
getting the chaining query format ... i dont know how to parse it but, what you are searching for is projection, you should take a look to http://docs.mongodb.org/manual/reference/operator/projection/
it would probably look like this :
user.findOne({email: params.username}, {'inventories.title': {$elemMatch: "activeInventory", 'invertories.vehicle.id': $elemMatch: params.vehicleId}, function(err, result) {
console.log(err);
console.log(result);
})

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