Links
Access to a collection
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var mongoClient = new MongoClient("MONGODB_CONNECTION_STRING");
var database = mongoClient.GetDatabase("DB_NAME");
var collection = database.GetCollection<MyClass>("COLLECTION_NAME");
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Find
Filter
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var builder = Builders<MyClass>.Filter;
FilterDefinition<MyClass> filter = builder.Empty;
filter &= builder.Exists(x => x.Property1);
filter &= builder.Eq(x => x.Property1, "id");
filter &= builder.In(x => x.Property1, new[] { "id1", "id2" }); // filter by Property1 equals to one of the ids
var result = await collection.Find(filter).ToListAsync();
var result = (await collection.FindAsync(filter)).ToList();
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Handle different types
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// get all the documents
var bsonDocumentCollection = database.GetCollection<BsonDocument>("MyCollection");
var filter = Builders<BsonDocument>.Filter.Empty;
var result = await bsonDocumentCollection.Find(filter).ToListAsync();
// get all the Class1 document
var class1Collection = database.GetCollection<Class1>("MyCollection");
await type1Collection.InsertOneAsync(new Class1 { Name = "Name1" });
var filter = Builders<Class1>.Filter.Eq(x => x.Type, nameof(Class1));
var filter = Builders<SimpleClass>.Filter.Exists(x => x.Name); // get all the documents which have a property Name
var result = await class1Collection.Find(filter).ToListAsync();
class Class1
{
public ObjectId Id { get; set; }
public string Name { get; set; } = string.Empty;
public string Type { get; set; } = nameof(Class1);
}
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Pipeline
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var stages = new BsonDocument[]
{
MatchStage(getTimeSeriesQuery),
ProjectionStage(),
SortStage()
};
var pipeline = PipelineDefinition<InputClass, OutputClass>.Create(stages);
var results = (await myCollection.AggregateAsync(pipeline)).List();
BsonDocument MatchStage(GetTimeSeriesQuery getTimeSeriesQuery)
{
var match = new BsonDocument("property1", "value1");
if (!string.IsNullOrEmpty(variable2))
{
match.AddRange(
new BsonDocument("property2", variable2)
);
}
return new BsonDocument("$match", match);
}
BsonDocument ProjectionStage() =>
new BsonDocument(
"$project",
new BsonDocument
{
{ "_id", 0 },
{ "property1", 1 },
{ "property2", 1 }
}
);
BsonDocument SortStage() =>
new BsonDocument("$sort", new BsonDocument("timestamp", 1));
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var mongoUrl = new MongoUrl("MONGODB_CONNECTION_STRING");
var mongoClientSettings = MongoClientSettings.FromUrl(mongoUrl);
mongoClientSettings.ClusterConfigurator = cb =>
{
cb.Subscribe<CommandStartedEvent>(e =>
{
logger.LogTrace($"{e.CommandName} - {e.Command.ToJson()}");
});
};
this.mongoClient = new MongoClient(mongoClientSettings);
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Configure the Log so it will be displayed in Visual Studio Output Debug window.
Errors
Requested value '_id' was not found
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await collection.Find(_ => true).ToListAsync();
// query with an id (the objects you want to retrieve must have a property ObjectId Id)
await collection.Find(x => x.Id == new ObjectId("...")).ToListAsync();
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Serializer for MyClass does not represent members as fields
Unable to deserialize a document into a Dictionary.
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public class MyClass : Dictionary<string, int>
{
public ObjectId Id { get; set; }
}
var collection = database.GetCollection<MyClass>(collectionName);
await collection.Find(x => x.Id == new ObjectId("...")).ToListAsync();
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