MongoDb c# driver find item in array by field value
There is ElemMatch var filter = Builders<Post>.Filter.ElemMatch(x => x.Tags, x => x.Name == “test”); var res = await collection.Find(filter).ToListAsync()
mongodb-.net-driver
MongoDB C# Driver 2.0 – Update document
I think you’re looking for ReplaceOneAsync(): MyType myObject; // passed in var filter = Builders<MyType>.Filter.Eq(s => s.Id, id); var result = await collection.ReplaceOneAsync(filter, myObject)
Get _id of an inserted document in MongoDB?
The Insert method automatically sets the property that is declared as the BSON ID of the model. If declared as follows… [BsonId] public ObjectId Id { get; set; } … then the Id field will contain the default (new, unique) BSON ID of the object after inserting the object into a collection: coll.Insert(obj); // obj.Id … Read more
How to deserialize a BsonDocument object back to class
There are three ways actually: 1.Specify type you want to load directly in FindAs<> var docs = _collection.FindAs<MyType>(_document); 2.Deserialize document via BsonSerializer: BsonSerializer.Deserialize<MyType>(doc); 3.Map bson document manually to your class: var myClass = new Mytype(); myClass.Name = bsonDoc[“name”].AsString; For most cases you are okay with first approach. But sometimes, when your documents is unstructured, you … Read more
Element ‘Id’ does not match any field or property of class
You can resolve the issue by adding [BsonIgnoreExtraElements] on top of the class declaration. ObjectId is internally maintained by MongoDB which may not be needed unless you want to get additional information such as timestamp from the object. Hope this helps.
Get All ‘documents’ from MongoDB ‘collection’
Using the current version of the driver (v2.0) you can do that by passing a filter that matches everything: var documents = await SpeCollection.Find(_ => true).ToListAsync(); They have also added an empty filter (FilterDefinition.Empty) which will arrive in the next version of the driver (v2.1): var documents = await SpeCollection.Find(Builders<Project>.Filter.Empty).ToListAsync();
Upserting in Mongo DB using official C# driver
Version 2 of the MongoDB C# driver requires setting the IsUpsert flag in the write commands. This example will upsert an entire document. var newDoc = new BsonDocument { { “_id”, 123 }, { “someKey”, “someValue” } }; var result = await collection.ReplaceOneAsync( filter: new BsonDocument(“_id”, 123), options: new ReplaceOptions { IsUpsert = true }, … Read more
MongoDB C# Driver: Ignore Property on Insert
It looks like the [BsonIgnore] attribute did the job. public class GroceryList : MongoEntity<ObjectId> { public FacebookList Owner { get; set; } [BsonIgnore] public bool IsOwner { get; set; } }
MongoDB and C#: Case insensitive search
The simplest and safest way to do that is using Linq: var names = namesCollection.AsQueryable().Where(name => name.FirstName.ToLower().Contains(“hamster”)); As explained in the tutorial ToLower, ToLowerInvariant, ToUpper and ToUpperInvariant all perform matches in a case insensitive way. After that you can use all the supported string methods like Contains or StartsWith. This example will generate: { “FirstName” … Read more
How to find min value in mongodb
You can use a combination of sort and limit to emulate min: > db.foo.insert({a: 1}) > db.foo.insert({a: 2}) > db.foo.insert({a: 3}) > db.foo.find().sort({a: 1}).limit(1) { “_id” : ObjectId(“4df8d4a5957c623adae2ab7e”), “a” : 1 } sort({a: 1}) is an ascending (minimum-first) sort on the a field, and we then only return the first document, which will be the … Read more