{
"_id" : NUUID("f5050a5d-b3be-4de6-a135-a119436fb511"),
"CoursesData" : [
{
"Name" : "Naturgræs",
"Value" : 1
}
],
"FacilityType" : {
"_id" : NUUID("a1b4844b-518b-40e2-8aa5-8ee399ac2d4e")
}
}
I want to retrieve a list with the distinct values from the field Name inside my object array of CourseData. Filtered by FacilityType._id. I tried using both $facet and the distinct operator, but it doesn't seems to like object arrays.
My result should look like this (or similar):
FacilityType (a1b4844b-518b-40e2-8aa5-8ee399ac2d4e),
CourseData: [Name1, Name2, Name3]
Update
From the answer given below, this is how you do it with the C# driver, if anyone needs to do the same.
FieldDefinition<FacilityDocument, string> field = "CoursesData.Name";
var result = FacilityCollection.Distinct(field, Builders<FacilityDocument>.Filter.Eq(x => x.FacilityType.ID, new Guid("a1b4844b-518b-40e2-8aa5-8ee399ac2d4e"))).ToList();
You can use distinct(). It will return distinct element for a specific field from document which match a query
For example if you want distinct value of Name field for facility "a1b4844b-518b-40e2-8aa5-8ee399ac2d4e", run this query:
db.collection.distinct("CoursesData.Name", {"FacilityType._id": "a1b4844b-518b-40e2-8aa5-8ee39ac2d4e"})
it will return :
[ "Naturgræs", ... ]
Related
I would like to preface this with saying that english is not my mother tongue, if any of my explanations are vague or don't make sense, please let me know and I will attempt to make them clearer.
I have a document containing some nested data. Currently product and customer are arrays, I would prefer to have them as straight up ObjectIDs.
{
"_id" : ObjectId("5bab713622c97440f287f2bf"),
"created_at" : ISODate("2018-09-26T13:44:54.431Z"),
"prod_line" : ObjectId("5b878e4c22c9745f1090de66"),
"entries" : [
{
"order_number" : "123",
"product" : [
ObjectId("5ba8a0e822c974290b2ea18d")
],
"customer" : [
ObjectId("5b86a20922c9745f1a6408d4")
],
"quantity" : "14"
},
{
"order_number" : "456",
"product" : [
ObjectId("5b878ed322c9745f1090de6c")
],
"customer" : [
ObjectId("5b86a20922c9745f1a6408d5")
],
"quantity" : "12"
}
]
}
I tried using the following query to update it, however that proved unsuccessful as Mongo didn't behave quite as I had expected.
db.Document.find().forEach(function(doc){
doc.entries.forEach(function(entry){
var entry_id = entry.product[0]
db.Document.update({_id: doc._id}, {$set:{'product': entry_id}});
print(entry_id)
})
})
With this query it sets product in the root of the object, not quite what I had hoped for. What I was hoping to do was to iterate through entries and change each individual product and customer to be only their ObjectId and not an array. Is it possible to do this via the mongo shell or do I have to look for another way to accomplish this? Thanks!
In order to accomplish your specified behavior, you just need to modify your query structure a bit. Take a look here for the specific MongoDB documentation on how to accomplish this. I will also propose an update to your code below:
db.Document.find().forEach(function(doc) {
doc.entries.forEach(function(entry, index) {
var productElementKey = 'entries.' + index + '.product';
var productSetObject = {};
productSetObject[productElementKey] = entry.product[0];
db.Document.update({_id: doc._id}, {$set: productSetObject});
print(entry_id)
})
})
The problem that you were having is that you were not updating the specific element within the entries array, but rather adding a new key to the top-level of the document named product. Generally, in order to set the value of an inner document within an array, you need to specify the array key first (entries in this case) and the inner document key second (product in this case). Since you are trying to set specific elements within the entries array, you need to also specify the index in your query object, I have specified above.
In order to update the customer key in the inner documents, simply switch out the product for customer in my above code.
You're trying to add a property 'product' directly into your document with this line
db.Document.update({_id: doc._id}, {$set:{'product': entry_id}});
Try to modify all your entries first, then update your document with this new array of entries.
db.Document.find().forEach(function(doc){
let updatedEntries = [];
doc.entries.forEach(function(entry){
let newEntry = {};
newEntry["order_number"] = entry.order_number;
newEntry["product"] = entry.product[0];
newEntry["customer"] = entry.customer[0];
newEntry["quantity"] = entry.quantity;
updatedEntries.push(newEntry);
})
db.Document.update({_id: doc._id}, {$set:{'entries': updatedEntries}});
})
You'll need to enumerate all the documents and then update the documents one and a time with the value store in the first item of the array for product and customer from each entry:
db.documents.find().snapshot().forEach(function (elem) {
elem.entries.forEach(function(entry){
db.documents.update({
_id: elem._id,
"entries.order_number": entry.order_number
}, {
$set: {
"entries.$.product" : entry.product[0],
"entries.$.customer" : entry.customer[0]
}
}
);
});
});
Instead of doing 2 updates each time you could possibly use the filtered positional operator to do all updates to all arrays items within one update query.
I have a situation where records in Mongo DB are like :
{
"_id" : "xxxx",
"_class" : "xxxx",
"orgId" : xxx,
"targetKeyToOrgIdMap" : {
"46784_56139542ecaa34c13ba9e314" : 46784,
"47530_562f1bc5fc1c1831d38d1900" : 47530,
"700004280_56c18369fc1cde1e2a017afc" : 700004280
},
}
I have to find out the records where child nodes of targetKeyToOrgIdMap has a particular set of values. That means, I know what the value is going to be there in the record in "46784_56139542ecaa34c13ba9e314" : 46784 part. And the field name is variable, its combination of the value and some random string.
In above example, I have 46784, and I need to find all the records which have 46784 in that respective field.
Is there any way I can fire some regex or something like that or by using any other mean where I would get the records which has the value I need in the child nodes of the field targetKeyToOrgIdMap.
Thanks in advance
You could use MongoDB's $where like this:
db.myCollection.find( { $where: function() {
for (var key in obj.targetKeyToOrgIdMap) {
if (obj.targetKeyToOrgIdMap[key] == 46784){
return true;
}
}
}}).each { obj ->
println obj
}
But be aware that this will require a full table scan where the function is executed for each document. See documentation.
I am new to querying dbs and especially mongodb.If I run :
db.<customers>.find({"contact_name: Anny Hatte"})
I get:
{
"_id" : ObjectId("55f7076079cebe83d0b3cffd"),
"company_name" : "Gap",
"contact_name" : "Anny Hatte",
"email" : "ahatte#gmail.com"
}
I wish to get the value of the "_id" attribute from this query result. How do I achieve that?
Similarly, if I have another collection, named items, with the following data:
{
"_id" : ObjectId("55f7076079cebe83d0b3d009"),
"_customer" : ObjectId("55f7076079cebe83d0b3cfda"),
"school" : "St. Patrick's"
}
Here, the "_customer" field is the "_id" of the customer collection (the previous collection). I wish to get the "_id", the "_customer" and the "school" field values for the record where "_customer" of items-collection equals "_id" of customers-collection.
How do I go about this?
I wish to get the value of the "_id" attribute from this query result.
How do I achieve that?
The find() method returns a cursor to the results, which you can iterate and retrieve the documents in the result set. You can do this using forEach().
var cursor = db.customers.find({"contact_name: Anny Hatte"});
cursor.forEach(function(customer){
//access all the attributes of the document here
var id = customer._id;
})
You could make use of the aggregation pipeline's $lookup stage that has been introduced as part of 3.2, to look up and fetch the matching rows in some other related collection.
db.customers.aggregate([
{$match:{"contact_name":"Anny Hatte"}},
{$lookup:{
"from":"items",
"localField":"_id",
"foreignField":"_customer",
"as":"items"
}}
])
In case you are using a previous version of mongodb where the stage is not supported, then, you would need to fire an extra query to lookup the items collection, for each customer.
db.customers.find(
{"contact_name":"Anny Hatte"}).map(function(customer){
customer["items"] = [];
db.items.find({"_customer":customer._id}).forEach(function(item){
customer.items.push(item);
})
return customer;
})
I have an array of ids and I want to get all document of them at once. For that I am writing but it return 0 records.
How can I search using multiple Ids ?
db.getCollection('feed').find({"_id" : { "$in" : [
"55880c251df42d0466919268","55bf528e69b70ae79be35006" ]}})
I am able to get records by passing single id like
db.getCollection('feed').find({"_id":ObjectId("55880c251df42d0466919268")})
MongoDB is type sensitive, which means 1 is different with '1', so are "55880c251df42d0466919268" and ObjectId("55880c251df42d0466919268"). The later one is in ObjectID type but not str, and also is the default _id type of MongoDB document.
You can find more information about ObjectID here.
Just try:
db.getCollection('feed').find({"_id" : {"$in" : [ObjectId("55880c251df42d0466919268"), ObjectId("55bf528e69b70ae79be35006")]}});
I believe you are missing the ObjectId. Try this:
db.feed.find({
_id: {
$in: [ObjectId("55880c251df42d0466919268"), ObjectId("55bf528e69b70ae79be35006")]
}
});
For finding records of multiple documents you have to use "$in" operator
Although your query is fine, you just need to add ObjectId while finding data for Ids
db.feed.find({
"_id" : {
"$in" :
[ObjectId("55880c251df42d0466919268"),
ObjectId("55bf528e69b70ae79be35006")
]
}
});
Just I have use it, and is working fine:
module.exports.obtenerIncidencias386RangoDias = function (empresas, callback) {
let arraySuc_Ids = empresas.map((empresa)=>empresa.sucursal_id)
incidenciasModel.find({'sucursal_id':{$in:arraySuc_Ids}
}).sort({created_at: 'desc'}).then(
(resp)=> {
callback(resp)}
)
};
where:
empresas = ["5ccc642f9e789820146e9cb0","5ccc642f9e789820146e9bb9"]
The Id's need to be in this format : ObjectId("id").
you can use this to transform your string ID's :
const ObjectId = require('mongodb').ObjectId;
store array list in var and pass that array list to find function
var list=db.collection_name.find()
db.collection_name.find({_id:{$in:list}})
db.getCollection({your_collection_name}).find({
"_id" : {
"$in" :
[({value1}),
({value2})
]
}
})
I'm trying to simulate a join in a mongo query so I'm taking the results of my 1st query and then passing it as a $in filter to my 2nd query.
Unfortunately the results of my 1st query returns an array of json objects like so
[ { _id: 4ecd830da046050100000025 },
{ _id: 4ecd84a0a046050100000085 } ]
and the $in filter doesn't return anything because they are json objects instead of a value array. I can manually transform that array but is there a built in method or function that I can use? Also, is there a way I can have mongo return the value array instead? Currently I am calling the find query as such
Likes.find {liker:"Me"}, {_id:1}, {safe:true}
And here is my 2nd query
Post.find {_id:{$in:likes}}
I was hoping for something like
Post.find {_id:{$in:likes._id}}
Although there is no general solution to your question in the case of $in clauses you can use the result of a distinct operation :
> db.test.save({a:1})
> db.test.save({a:2})
> db.test.save({a:3})
> db.test.save({a:4})
> ids = db.test.distinct("_id", {a:{$gt:2}})
[
ObjectId("4ece45c2c951f11718678574"),
ObjectId("4ece45c4c951f11718678575")
]
> db.test.find({_id:{$in:ids}})
{ "_id" : ObjectId("4ece45c2c951f11718678574"), "a" : 3 }
{ "_id" : ObjectId("4ece45c4c951f11718678575"), "a" : 4 }
Hope that helps!