Related
I want to remove a topic by id from the following collection. Here is the hierarchy of the collection - Area.
Area ---
|
---Subjects---
|
Courses---
|
Chapters----
|
Topics
The Area example is as following.
{
"_id" : ObjectId("607f7c67f64e993a5c9b9793"),
"name" : "Automatic Engineering",
"description" : "this is the description.",
"created" : ISODate("2021-04-21T01:14:15.736Z"),
"subjects" : [
{
"description" : "dddd",
"name" : "Transfer Function",
"_id" : ObjectId("607f7c7af64e993a5c9b9794"),
"created" : ISODate("2021-04-21T01:14:34.943Z"),
"courses" : [
{
"description" : "dddd",
"name" : "conception",
"_id" : ObjectId("607f7c9af64e993a5c9b9796"),
"created" : ISODate("2021-04-21T01:15:06.696Z"),
"chapters" : [
{
"description" : "chapter 1",
"name" : "Chapter 1",
"_id" : ObjectId("607f7cb4f64e993a5c9b9798"),
"created" : ISODate("2021-04-21T01:15:32.855Z"),
"topics" : [
{
"description" : "1",
"name" : "Topic 1",
"_id" : ObjectId("607f7ccef64e993a5c9b979b"),
"created" : ISODate("2021-04-21T01:15:58.064Z")
},
{
"description" : "2",
"name" : "Topic 2",
"_id" : ObjectId("607f7cd5f64e993a5c9b979c"),
"created" : ISODate("2021-04-21T01:16:05.663Z")
},
{
"description" : "3",
"name" : "Topic 3",
"_id" : ObjectId("607f7cdcf64e993a5c9b979d"),
"created" : ISODate("2021-04-21T01:16:12.336Z")
}
]
},
{
"description" : "chapter2",
"name" : "Chapter 2",
"_id" : ObjectId("607f7cbcf64e993a5c9b9799"),
"created" : ISODate("2021-04-21T01:15:40.231Z"),
"topics" : []
},
{
"description" : "chapter 3",
"name" : "Chapter 3",
"_id" : ObjectId("607f7cc5f64e993a5c9b979a"),
"created" : ISODate("2021-04-21T01:15:49.000Z"),
"topics" : []
}
]
},
{
"description" : "dddd",
"name" : "exercise",
"_id" : ObjectId("607f7ca6f64e993a5c9b9797"),
"created" : ISODate("2021-04-21T01:15:18.465Z"),
"chapters" : []
}
]
},
{
"description" : "this is the example",
"name" : "State Space Equation",
"_id" : ObjectId("607f7c8ef64e993a5c9b9795"),
"created" : ISODate("2021-04-21T01:14:54.056Z"),
"courses" : []
}
],
"__v" : 0
}
And I need to remove topic object in chapters array. So this is what I have done.
areaModel.findOneAndUpdate({
'_id': req.body.area_id,
'subjects._id': req.body.subject_id,
'courses._id': req.body.course_id,
'chapter._id': req.body.chapter_id
}, {
"$pull": {
"subjects.$.courses.$.chapters.$.topics": {
_id: req.body.topic_id
}
}
}, (err, result) =>{
if (err) {
return res.json({success: false, msg: err});
} else {
return res.json({success: true, msg:"successfully removed" });
}
});
By using $pull method of mongoose, I could remove the course from the area easily. But it was impossible for me to remove the more nested items like chapters and topics.
How can I solve this issue?
you can do so with the use of arrayFilters like so:
db.collection.updateOne(
{
_id: ObjectId("607f7c67f64e993a5c9b9793")
},
{
$pull: {
"subjects.$[s].courses.$[c].chapters.$[ch].topics": {
_id: ObjectId("607f7ccef64e993a5c9b979b")
}
}
},
{
arrayFilters: [
{
"s._id": { $eq: ObjectId("607f7c7af64e993a5c9b9794") }
},
{
"c._id": { $eq: ObjectId("607f7c9af64e993a5c9b9796") }
},
{
"ch._id": { $eq: ObjectId("607f7cb4f64e993a5c9b9798") }
}
]
})
https://mongoplayground.net/p/kVyV27nnkII
Try it:
areaModel.findOneAndUpdate(
{ _id: req.body.area_id },
{
$pull: {
"subjects.$[].courses.$[].chapters.$[].topics": {
_id: req.body.topic_id,
},
},
}
);
I am having problems aggregating my Product Document in MongoDB.
My Product Document is:
{
"_id" : ObjectId("5d81171c2c69f45ef459e0af"),
"type" : "T-Shirt",
"name" : "Panda",
"description" : "Panda's are cool.",
"image" : ObjectId("5d81171c2c69f45ef459e0ad"),
"created_at" : ISODate("2019-09-17T18:25:48.026+01:00"),
"is_featured" : false,
"sizes" : [
"XS",
"S",
"M",
"L",
"XL"
],
"tags" : [ ],
"pricing" : {
"price" : 26,
"sale_price" : 8
},
"categories" : [
ObjectId("5d81171b2c69f45ef459e086"),
ObjectId("5d81171b2c69f45ef459e087")
],
"sku" : "5d81171c2c69f45ef459e0af"
},
And my Category Document is:
{
"_id" : ObjectId("5d81171b2c69f45ef459e087"),
"name" : "Art",
"description" : "These items are our artsy options.",
"created_at" : ISODate("2019-09-17T18:25:47.196+01:00")
},
My aim is to perform aggregation on the Product Document in order to count the number of items within each Category. So I have the Category "Art", I need to count the products are in the "Art" Category:
My current aggregate:
db.product.aggregate(
{ $unwind : "$categories" },
{
$group : {
"_id" : { "name" : "$name" },
"doc" : { $push : { "category" : "$categories" } },
}
},
{ $unwind : "$doc" },
{
$project : {
"_id" : 0,
"name" : "$name",
"category" : "$doc.category"
}
},
{
$group : {
"_id" : "$category",
"name": { "$first": "$name" },
"items_in_cat" : { $sum : 1 }
}
},
{ "$sort" : { "items_in_cat" : -1 } },
)
Which does actually work but not as I need:
{
"_id" : ObjectId("5d81171b2c69f45ef459e082"),
"name" : null, // Why is the name of the category no here?
"items_in_cat" : 4
},
As we can see the name is null. How can I aggregate the output to be:
{
"_id" : ObjectId("5d81171b2c69f45ef459e082"),
"name" : "Art",
"items_in_cat" : 4
},
We need to use $lookup to fetch the name from Category collection.
The following query can get us the expected output:
db.product.aggregate([
{
$unwind:"$categories"
},
{
$group:{
"_id":"$categories",
"items_in_cat":{
$sum:1
}
}
},
{
$lookup:{
"from":"category",
"let":{
"id":"$_id"
},
"pipeline":[
{
$match:{
$expr:{
$eq:["$_id","$$id"]
}
}
},
{
$project:{
"_id":0,
"name":1
}
}
],
"as":"categoryLookup"
}
},
{
$unwind:{
"path":"$categoryLookup",
"preserveNullAndEmptyArrays":true
}
},
{
$project:{
"_id":1,
"name":{
$ifNull:["$categoryLookup.name","NA"]
},
"items_in_cat":1
}
}
]).pretty()
Data set:
Collection: product
{
"_id" : ObjectId("5d81171c2c69f45ef459e0af"),
"type" : "T-Shirt",
"name" : "Panda",
"description" : "Panda's are cool.",
"image" : ObjectId("5d81171c2c69f45ef459e0ad"),
"created_at" : ISODate("2019-09-17T17:25:48.026Z"),
"is_featured" : false,
"sizes" : [
"XS",
"S",
"M",
"L",
"XL"
],
"tags" : [ ],
"pricing" : {
"price" : 26,
"sale_price" : 8
},
"categories" : [
ObjectId("5d81171b2c69f45ef459e086"),
ObjectId("5d81171b2c69f45ef459e087")
],
"sku" : "5d81171c2c69f45ef459e0af"
}
Collection: category
{
"_id" : ObjectId("5d81171b2c69f45ef459e086"),
"name" : "Art",
"description" : "These items are our artsy options.",
"created_at" : ISODate("2019-09-17T17:25:47.196Z")
}
{
"_id" : ObjectId("5d81171b2c69f45ef459e087"),
"name" : "Craft",
"description" : "These items are our artsy options.",
"created_at" : ISODate("2019-09-17T17:25:47.196Z")
}
Output:
{
"_id" : ObjectId("5d81171b2c69f45ef459e087"),
"items_in_cat" : 1,
"name" : "Craft"
}
{
"_id" : ObjectId("5d81171b2c69f45ef459e086"),
"items_in_cat" : 1,
"name" : "Art"
}
I have the below document which contains double nested array format. I have to update the "level" field to "Senior Engineer" when the "someKey":"somevalue" and "Company":"Company1" and "Name":"Nandhi".
Document
{
"_id" : "777",
"someKey" : "someValue",
"someArray" : [
{
"Company" : "Company1",
"someNestedArray" : [
{
"name" : "Nandhi",
"level" : "Junior Engineer"
},
{
"name" : "Rajan",
"level" : "Senio Engineer"
}
]
}],
{
"Company" : "Company2",
"someNestedArray" : [
{
"name" : "Nandhi",
"level" : "Junior Engineer"
},
{
"name" : "Rajan",
"level" : "Senio Engineer"
}
]
}
]
}
Update Query I tried
db.Test123.updateOne(
{"someKey" : "someValue","someArray.Company":"Company1"},
{$set:{"someArray.$[someNestedArray].level":"Senior Developer"}},
{arrayFilters:[{"someNestedArray.name":"Nandhi"}]}
);
Output Screenshot
As you can seen that, the modifiedCount returns 0. Please advice on this!
You need to define arrayFilter for every level of nesting, try:
db.Test123.update(
{ "someKey" : "someValue" },
{ "$set": { "someArray.$[someArrayDoc].someNestedArray.$[someNestedArrayDoc].level": "Senior Developer" } },
{ arrayFilters: [ {"someArrayDoc.Company": "Company1"}, { "someNestedArrayDoc.name": "Nandhi" } ] }
)
I have datas of following format collection(projects) inside my database:
{ "_id" : ObjectId("5981a80f223e491a58230e5d"), "id" : 2, "name" : "gbqplhlqxzwl", "managerId" : 65151, "startDate" : "03.11.1999", "finishDate" : "02.01.2003", "projectStatus" : "POSTPONED", "participants" : [ ], "estimatedBudget" : 6017891.811079914 }
{ "_id" : ObjectId("5981a80f223e491a58230e5e"), "id" : 3, "name" : "erfekfsdgryu", "managerId" : 83749, "startDate" : "07.07.2007", "finishDate" : "26.12.2027", "projectStatus" : "POSTPONED", "participants" : [ 19229, 81856, 79270, 5509, 70344, 39424 ], "estimatedBudget" : 3086213.8981674756 }
{ "_id" : ObjectId("5981a80f223e491a58230e5f"), "id" : 1, "name" : "jvbzobhppntd", "managerId" : 18925, "startDate" : "29.04.1999", "finishDate" : "13.10.2008", "projectStatus" : "OPEN", "participants" : [ 46100, 96968, 6676, 56121, 4716, 68901, 43990, 48587, 62547, 30292, 65153, 17551, 27083, 20261, 27097, 50036, 86585, 69890, 18790, 22592, 60774, 93709, 78471, 27157, 4328, 36501, 47296, 16831 ], "estimatedBudget" : 3581496.7068344904 }
{ "_id" : ObjectId("5981a80f223e491a58230e60"), "id" : 4, "name" : "cdspkkqwvwld", "managerId" : 62042, "startDate" : "13.03.1998", "finishDate" : "20.06.2007", "projectStatus" : "OPEN", "participants" : [ 53480, 60897, 23677, 22064, 60807, 66637, 84609, 28378, 87143, 27675, 79283, 94992, 20429, 48769, 91671, 41747, 21651, 91134, 41684, 57228, 51949, 18756, 45679, 87781, 67287, 6902, 27526 ], "estimatedBudget" : 2126283.953787842 }
....
I need to find the busiest employee and list all his projects.
participants array contains employee ids who participate in the project.
I use the following query to find the busiest employee:
db.projects.aggregate(
{
$unwind: '$participants'
},
{
$addFields: {
count: 1
}
},
{
$group: {
_id : '$participants',
participation_count : {
'$sum':'$count'
}
}
},
{
$sort:{participation_count:-1}
},
{
$limit:1
}
)
and this work correctly. But I have no ideas how to list all his projects.
any ideas?
db.projects.aggregate(
[
{
$unwind: '$participants'
},
{
$addFields: {
count: 1
}
},
{
$group: {
_id : '$participants',
participation_count : {'$sum':'$count'},
projectId : {$push: '$id'}
}
},
{
$sort:{participation_count:-1}
},
{
$limit:1
}
],
{
allowDiskUse:true
}
)
I am trying to port an existing SQL schema into Mongo.
We have document tables, with sometimes several times the same document, with a different revision but the same reference. I want to get only the latest revisions of the documents.
A sample input data:
{
"Uid" : "xxx",
"status" : "ACCEPTED",
"reference" : "DOC305",
"code" : "305-D",
"title" : "Document 305",
"creationdate" : ISODate("2011-11-24T15:13:28.887Z"),
"creator" : "X"
},
{
"Uid" : "xxx",
"status" : "COMMENTED",
"reference" : "DOC306",
"code" : "306-A",
"title" : "Document 306",
"creationdate" : ISODate("2011-11-28T07:23:18.807Z"),
"creator" : "X"
},
{
"Uid" : "xxx",
"status" : "COMMENTED",
"reference" : "DOC306",
"code" : "306-B",
"title" : "Document 306",
"creationdate" : ISODate("2011-11-28T07:26:49.447Z"),
"creator" : "X"
},
{
"Uid" : "xxx",
"status" : "ACCEPTED",
"reference" : "DOC501",
"code" : "501-A",
"title" : "Document 501",
"creationdate" : ISODate("2011-11-19T06:30:35.757Z"),
"creator" : "X"
},
{
"Uid" : "xxx",
"status" : "ACCEPTED",
"reference" : "DOC501",
"code" : "501-B",
"title" : "Document 501",
"creationdate" : ISODate("2011-11-19T06:40:32.957Z"),
"creator" : "X"
}
Given this data, I want this result set (sometimes I want only the last revision, sometimes I want all revisions with an attribute telling me whether it's the latest):
{
"Uid" : "xxx",
"status" : "ACCEPTED",
"reference" : "DOC305",
"code" : "305-D",
"title" : "Document 305",
"creationdate" : ISODate("2011-11-24T15:13:28.887Z"),
"creator" : "X",
"lastrev" : true
},
{
"Uid" : "xxx",
"status" : "COMMENTED",
"reference" : "DOC306",
"code" : "306-B",
"title" : "Document 306",
"creationdate" : ISODate("2011-11-28T07:26:49.447Z"),
"creator" : "X",
"lastrev" : true
},
{
"Uid" : "xxx",
"status" : "ACCEPTED",
"reference" : "DOC501",
"code" : "501-B",
"title" : "Document 501",
"creationdate" : ISODate("2011-11-19T06:40:32.957Z"),
"creator" : "X",
"lastrev" : true
}
I already have a bunch of filters, sorting, and skip/limit (for pagination of data), so the final result set should be mindful of these constraints.
The current "find" query (built with the .Net driver), which filters fine but gives me all revisions of each document:
coll.find(
{ "$and" : [
{ "$or" : [
{ "deletedid" : { "$exists" : false } },
{ "deletedid" : null }
] },
{ "$or" : [
{ "taskid" : { "$exists" : false } },
{ "taskid" : null }
] },
{ "objecttypeuid" : { "$in" : ["xxxxx"] } }
] },
{ "_id" : 0, "Uid" : 1, "lastrev" : 1, "title" : 1, "code" : 1, "creator" : 1, "owner" : 1, "modificator" : 1, "status" : 1, "reference": 1, "creationdate": 1 }
).sort({ "creationdate" : 1 }).skip(0).limit(10);
Using another question, I have been able to build this aggregation, which gives me the latest revision of each document, but with not enough attributes in the result:
coll.aggregate([
{ $sort: { "creationdate": 1 } },
{
$group: {
"_id": "$reference",
result: { $last: "$creationdate" },
creationdate: { $last: "$creationdate" }
}
}
]);
I would like to integrating the aggregate with the find query.
I have found the way to mix aggregation and filtering:
coll.aggregate(
[
{ $match: {
"$and" : [
{ "$or" : [
{ "deletedid" : { "$exists" : false } },
{ "deletedid" : null }
] },
{ "$or" : [
{ "taskid" : { "$exists" : false } },
{ "taskid" : null }
] },
{ "objecttypeuid" : { "$in" : ["xxx"] } }
]
}
},
{ $sort: { "creationdate": 1 } },
{ $group: {
"_id": "$reference",
"doc": { "$last": "$$ROOT" }
}
},
{ $sort: { "doc.creationdate": 1 } },
{ $skip: skip },
{ $limit: limit }
],
{ allowDiskUse: true }
);
For each result node, this gives me a "doc" node with the document data. It has too much data still (it's missing projections), but it's a start.
Translated in .Net:
FilterDefinitionBuilder<BsonDocument> filterBuilder = Builders<BsonDocument>.Filter;
FilterDefinition<BsonDocument> filters = filterBuilder.Empty;
filters = filters & (filterBuilder.Not(filterBuilder.Exists("deletedid")) | filterBuilder.Eq("deletedid", BsonNull.Value));
filters = filters & (filterBuilder.Not(filterBuilder.Exists("taskid")) | filterBuilder.Eq("taskid", BsonNull.Value));
foreach (var f in fieldFilters) {
filters = filters & filterBuilder.In(f.Key, f.Value);
}
var sort = Builders<BsonDocument>.Sort.Ascending(orderby);
var group = new BsonDocument {
{ "_id", "$reference" },
{ "doc", new BsonDocument("$last", "$$ROOT") }
};
var aggregate = coll.Aggregate(new AggregateOptions { AllowDiskUse = true })
.Match(filters)
.Sort(sort)
.Group(group)
.Sort(sort)
.Skip(skip)
.Limit(rows);
return aggregate.ToList();
I'm pretty sure there are better ways to do this, though.
You answer is pretty close. Instead of $last, $max is better.
About $last operator:
Returns the value that results from applying an expression to the last document in a group of documents that share the same group by a field. Only meaningful when documents are in a defined order.
Get the last revision in each group, see code below in mongo shell:
db.collection.aggregate([
{
$group: {
_id: '$reference',
doc: {
$max: {
"creationdate" : "$creationdate",
"code" : "$code",
"Uid" : "$Uid",
"status" : "$status",
"title" : "$title",
"creator" : "$creator"
}
}
}
},
{
$project: {
_id: 0,
Uid: "$doc.Uid",
status: "$doc.status",
reference: "$_id",
code: "$doc.code",
title: "$doc.title",
creationdate: "$doc.creationdate",
creator: "$doc.creator"
}
}
]).pretty()
The output as your expect:
{
"Uid" : "xxx",
"status" : "ACCEPTED",
"reference" : "DOC501",
"code" : "501-B",
"title" : "Document 501",
"creationdate" : ISODate("2011-11-19T06:40:32.957Z"),
"creator" : "X"
}
{
"Uid" : "xxx",
"status" : "COMMENTED",
"reference" : "DOC306",
"code" : "306-B",
"title" : "Document 306",
"creationdate" : ISODate("2011-11-28T07:26:49.447Z"),
"creator" : "X"
}
{
"Uid" : "xxx",
"status" : "ACCEPTED",
"reference" : "DOC305",
"code" : "305-D",
"title" : "Document 305",
"creationdate" : ISODate("2011-11-24T15:13:28.887Z"),
"creator" : "X"
}