I have got a collection of documents and each documents contains a nested array of objects.
{
"id": "309324739",
"debters": [
{
"user": {
"name": "John Doe",
"internal": true
},
"debt": 1463,
},
{
"user": {
"name": "Alex Tree",
"internal": false
},
"debt": 53443,
},
}
What I'm trying to do is to return find the document by id and then find inside the debters list that has a false flag?
I tried the following query...
Debters findByIdAndDebters_User_InternalIsFalse(#Param("id") String id,);
But I'm getting an error saying that it can find "internal" property. What am I doing wrong and how can I loop through array using this magic mongo repository query?
you need to write a native query for that which is similar to
#Query("{'debters.user.internal':false,'_id':''}")
Debters findByIdAndDebtersUserInternalIsFalse(#Param("id") String id,);
Related
I have a collection in MongoDB containing search history of a user where each document is stored like:
"_id": "user1"
searchHistory: {
"product1": [
{
"timestamp": 1623482432,
"query": {
"query": "chocolate",
"qty": 2
}
},
{
"timestamp": 1623481234,
"query": {
"query": "lindor",
"qty": 4
}
},
],
"product2": [
{
"timestamp": 1623473622,
"query": {
"query": "table",
"qty": 1
}
},
{
"timestamp": 1623438232,
"query": {
"query": "ike",
"qty": 1
}
},
]
}
Here _id of document acts like a foreign key to the user document in another collection.
I have backend running on nodejs and this function is used to store a new search history in the record.
exports.updateUserSearchCount = function (userId, productId, searchDetails) {
let addToSetData = {}
let key = `searchHistory.${productId}`
addToSetData[key] = { "timestamp": new Date().getTime(), "query": searchDetails }
return client.db("mydb").collection("userSearchHistory").updateOne({ "_id": userId }, { "$addToSet": addToSetData }, { upsert: true }, async (err, res) => {
})
}
Now, I want to get search history of a user based on query only using the db.find().
I want something like this:
db.find({"_id": "user1", "searchHistory.somewildcard.query": "some query"})
I need a wildcard which will replace ".somewildcard." to search in all products searched.
I saw a suggestion that we should store document like:
"_id": "user1"
searchHistory: [
{
"key": "product1",
"value": [
{
"timestamp": 1623482432,
"query": {
"query": "chocolate",
"qty": 2
}
}
]
}
]
However if I store document like this, then adding search history to existing document becomes a tideous and confusing task.
What should I do?
It's always a bad idea to save values are keys, for this exact reason you're facing. It heavily limits querying that field, obviously the trade off is that it makes updates much easier.
I personally recommend you do not save these searches in nested form at all, this will cause you scaling issues quite quickly, assuming these fields are indexed you will start seeing performance issues when the arrays get's too large ( few hundred searches ).
So my personal recommendation is for you to save it in a new collection like so:
{
"user_id": "1",
"key": "product1",
"timestamp": 1623482432,
"query": {
"query": "chocolate",
"qty": 2
}
}
Now querying a specific user or a specific product or even a query substring is all very easily supported by creating some basic indexes. an "update" in this case would just be to insert a new document which is also much faster.
If you still prefer to keep the nested structure, then I recommend you do switch to the recommended structure you posted, as you mentioned updates will become slightly more tedious, but you can still do it quite easily using arrayFilters for updating a specific element or just using $push for adding a new search
I am new to NoSQL and morphia. I am using Morphia to query MongoDB.
I have a sample collection as below:
[
{
"serviceId": "id1",
"serviceName": "ding",
"serviceVersion": "1.0",
"files": [
{
"fileName": "b.html",
"fileContents": "contentsA"
},
{
"fileName": "b.html",
"fileContents": "contentsB"
}
]
},
{
"serviceId": "id2",
"serviceName": "ding",
"serviceVersion": "2.0",
"files": [
{
"fileName": "b.html",
"fileContents": "contentsA"
},
{
"fileName": "b.html",
"fileContents": "contentsB"
}
]
}
]
I would like to fetch an element in "files" List , given service name, service version and filename., using Morphia.
I was able to get what I want using the query below:
db.ApiDoc.find({ serviceName: "ding", serviceVersion: "2.0"}, { files: { $elemMatch: { fileName: "b.html" } } }).sort({ "_id": 1}).skip(0).limit(30);
What I tried so far :
I tried using "elemmatch" api that morphia has, but no luck.
query = ...createQuery(
Result.class);
query.and(query.criteria("serviceName").equal("ding"),
query.criteria("serviceVersion").equal(
"2.0"));
query.filter("files elem",BasicDBObjectBuilder.start("fileName", "a.html").get());
I seem to get the entire Result collection with all the files. I would like to get only the matched files(by filename).
can some one help me how I can get this to work?
Thanks
rajesh
I don't believe it's possible to get just the matching sub element. You can request just to have the 'files' array returned but all elements will be included in the result set and you will have to refilter in your code.
The other option is to make Files a collection of its own with a serviceId field and then you'll have more power to load only certain files.
It's possible to do that.
the filter doesn't really work like projection.
try this :
datastore.createQuery(Result.class)
.field("serviceName").equal("dong")
.field("serviceVersion").equal("2.0")
.field("files.filename").equal("a.html")
.project("files.$.filename", true);
Assuming this data structure:
{
"title": "Foo bar",
"username": "jackwreid"
},
{
"title": "Bish bosh",
"username": "lizziebump"
},
{
"title": "Ham nam",
"username": "lizziebump"
},
{
"title": "Blub blub",
"username": "jvarn"
}
And assuming
var userFollowing = ["lizziebump", "jackwreid"]
How would I do a db.posts.find() for posts where the username matches any of the contents of the userFollowing array?
I'm trying to build a query that returns posts by users in the current user's following list and I can only find docs on how to do this the other way around where the query returns posts if a single query string is in any array position.
You can use the $in operator
db.collection.find({username: {$in: userFollowing}})
Is it possible to query mongodb to return array of matching document id values, without the related keys?
Please consider following 'parent' data structur:
{
"_id": ObjectId("52448e4697fb2b775cb5c3a7"),
"name": "Peter",
"children": [
{
"name": "joe"
}
]
},
{
"_id": ObjectId("52448e4697fb2b775cb5c3b6"),
"name": "Marry",
"children": [
{
"name": "joe"
}
]
}
I would to query for an array of parent _ids whose children have the name "joe"
For provided sample data, I would like the following output returned from mongo:
[ObjectId("52448e4697fb2b775cb5c3a7"), ObjectId("52448e4697fb2b775cb5c3b6")]
I know that I can query for an output like this, which also contains the keys
[{"_id": ObjectId("52448e4697fb2b775cb5c3a7")}, {"_id": ObjectId("52448e4697fb2b775cb5c3b6")}]
However I need to push above array to another document with an update operation like this:
db.statistic.update({"date": today}, {$push: {"children": [ObjectId("52448e4697fb2b775cb5c3a7"), ObjectId("52448e4697fb2b775cb5c3b6")]}}, true, false)
I would like to avoid sorting out the document structure, in case it is possible to just return an array containing the appropriate values using mongo
It should be possible by
db.coll.distinct("_id", {"children.name": "joe"})
I've the following entity persisted on mongo in a users collection:
{
"fullname": "Luke Tomson",
"nicknames": [
{
"name": "lukeone",
"created": ISODate("2011-05-18T19:42:56.411Z")
},
{
"name": "magicluke",
"created": ISODate("2012-01-12T19: 42: 56.411Z")
},
{
"name": "superluke",
"created": ISODate("2012-03-27T19: 42: 56.411Z")
}
}
]
}
How do I get the last nickname name for a user whose fullname is "Luke Tomson" ? And more specifically, how do I retrieve in the mongo shell a specific index (the first or the last) of a sorted array that was sorted upon a specific field (in this case, created).
Thanks
From the documentation, the second object passed to a .find is a selection of what portions of the object you want returned.
So, what you want is basically:
db.users.find({"fullname": "Luke Tomson"}, {"nicknames": { $slice: -1 } });
Though you might also want to return the _id if there are multiple "Luke Tomson"s in your DB and you need to uniquely identify them.