mongodb

问题 I am new to Java custom annotations I am developing a custom annotation which encrypt and decrypt a string and store it in database using spring and mongodb and for encryption I am using jasypt. I am not getting the exact procedure to do so. My code. Entity public class Demo { @Id private Long id; private String somethingPublic; @EncryptDemo() private String somethingPrivate; //getter setter } custom annotation @Target({ ElementType.METHOD, ElementType.FIELD }) @Retention(RetentionPolicy

问题 This specifc question is in relation to using mongodb with the golang package mongo-driver, but I would assume this applies across most interfaces with mongodb. When using Find to query some data from a collection, we can use both the bson.M- and bson.D-type to specify the filter for this find. As per the documentation bson.D should be used if the order of elements matters and bson.M should be used otherwise. D is an ordered representation of a BSON document. This type should be used when the

问题 I am using python. Now I have a mongoDB database collection, in which all documents have such a format: {"_id":ObjectId("53590a43dc17421e9db46a31"), "latlng": {"type" : "Polygon", "coordinates":[[[....],[....],[....],[....],[.....]]]} "self":{"school":2,"home":3,"hospital":6} } In which the field "self" indicates the venue types in the Polygon and the number of corresponding venue types. different documents have different self field, such as {"KFC":1,"building":2,"home":6}, {"shopping mall":1

问题 I am currently working on an application which allows users to save sensitive date. Since it's a web application we are using NodeJS and MongoDB for persistence. (BTW I am completely new to Node and NoSQL) We do have users who can store kind of a medical history. Name and email are stored within a user document while the other stuff is stored within the profile. To improve security I would like to encrypt the references from a user to his profile and vice versa. At the moment I am using the

问题 When using MongoDB's $in clause with Aggregate , Does That has any max limit in number of arguments ? for example Model.aggregate( [ { $match : { '_Id' : { $in : ids } } } , { $group : { _id : '$roomId' , maxdate: { $max: "$date"}, } }, {$sort: { maxdate: -1} }, {$skip: skip}, {$limit: limitNum } ] In ids array , how many ids i can pass ? Currently i am not facing any issue with ids length till 50,000 ... but for safe side wanted to know the max limit. I have tried to search on Mongo doc ,

问题 I'm trying to find an easy way to sync data in mongoDB 4.x, to elasticsearch 6.x . My use case is for partial text search that is supported by elasticsearch but no supported by mongodb. MongoDB is the primary database for my applications. All solutions i found seem outdated and only support older version of mongoDB / elasticsearch. These include mongodb-connector, mongodb river What is the best tool to use so that any changes (CRUD) to data in mongoDB is automatically synced to elasticsearch?

问题 Whenever I run a count query on MongoDB with explain I can see two different stages COUNT_SCAN and IXSCAN. I want to know the difference between them according to performance and how can I improve the query. field is indexed. query db.collection.explain(true).count({field:1}}) uses COUNT_SCAN and query like db.collection.explain(true).count({field:"$in":[1,2]}) uses IXSCAN. 回答1: The short: COUNT_SCAN is the most efficient way to get a count by reading the value from an index, but can only be

问题 IMongoDatabase does not support db.GetStats(); which is deprecated in new version. I want to try alternate approach to get database stats. I use the following code to run command as we can get the stats from shell: var client = new MongoClient("mongodb://localhost:27017/analytics"); var db = client.GetDatabase("analytics"); var stats = db.RunCommand<BsonDocument>("db.stats()"); var collectionNames = db.RunCommand<BsonDocument> ("db.getCollectionNames()"); I am getting following error here:

问题 I have successfully stored image files in mongdb in binary format.but when i m getting image from mongodb i m getting the same banary format.But i need this image file.Please someone could help This is the code i used def retrieve(request): db=pymongo.connection.Connection('localhost',27017).demo1 grid=gridfs.GridFS(db) output=grid.get_last_version(filename='shiva.jpg') return HttpResponse(output) 回答1: Hi i have successfully inserted and retrieved image from mongodb with python.. def insert

问题 I am building an app and I have create 2 models. const UserSchema = new Schema({ _id: Schema.Types.ObjectId, account:{ type: String, unique: true }, email: String, first_name: String, last_name: String } const VenueSchema = new Schema({ _id: Schema.Types.ObjectId, venue_type: String, capacity: Number }) and const MediatorSchema = new Schema({ _id: Schema.Types.ObjectId, account:{ type: String, unique: true }, user: {type: Schema.Types.ObjectId, ref:'User' } venue: {type: Schema.Types.ObjectId