Usando polimorfismo com MongoDB e C#

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var vehiclesColl = db.CreateCollection<Vehicle>("vehicles");

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await vehiclesColl.InsertOneAsync(new Car());

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{
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  "_id": ObjectId("660d7d43e042f8f6f2726f6a"),
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  "_t": "Car",
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  // ... fields for vehicle 
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  // ... fields specific to car
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}

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[BsonKnownTypes(typeof(Car), typeof(Motorcycle))]
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public abstract class Vehicle
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{
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    // ...
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}

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[BsonDiscriminator(RootClass = true)]
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[BsonKnownTypes(typeof(Car), typeof(Motorcycle))]
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public abstract class Vehicle
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{
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    // ...
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}

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{
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  "_id": ObjectId("660d81e5825f1c064024a591"),
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  "_t": [
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    "Vehicle",
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    "Car"
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  ],
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  // ...
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}

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var vehiclesColl = db.GetCollection<Vehicle>("vehicles");
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var vehicles = (await vehiclesColl.FindAsync(FilterDefinition<Vehicle>.Empty))
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    .ToEnumerable();

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var carsColl = vehiclesColl.OfType<Car>();
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var cars = (await carsColl.FindAsync(FilterDefinition<Car>.Empty))
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    .ToEnumerable();

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await carsColl.DeleteManyAsync(FilterDefinition<Car>.Empty);

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var cars = vehiclesColl.AsQueryable().OfType<Car>();

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using MongoDB.Bson;
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using MongoDB.Bson.Serialization.Attributes;
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public abstract class BaseDocument
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{
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    [BsonRepresentation(BsonType.ObjectId)]
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    public string Id { get; set; } = ObjectId.GenerateNewId().ToString();
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    [BsonRepresentation(BsonType.ObjectId)]
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    public string SiteId { get; set; } = ObjectId.GenerateNewId().ToString();
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    public string Name { get; set; } = string.Empty;
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    public Measurement? Last { get; set; }
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}
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public class Measurement
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{
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    public int Value { get; set; }
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    public DateTime Timestamp { get; set; }
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}
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public class Address
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{
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  // ...
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}
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public class SiteOverview : BaseDocument
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{
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    public Address Address { get; set; } = new();
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}
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public class SensorDetail : BaseDocument
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{
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    public string Location { get; set; } = string.Empty;
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}

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async Task IngestMeasurementAsync(
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    IMongoCollection<BaseDocument> overviewsColl,
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    string sensorId,
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    int value)
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{
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    var measurement = new Measurement()
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    {
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        Value = value,
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        Timestamp = DateTime.UtcNow
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    };
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    var sensorUpdate = Builders<SensorDetail>
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        .Update
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        .Set(x => x.Last, measurement);
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    var sensorDetail = await overviewsColl
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        .OfType<SensorDetail>()
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        .FindOneAndUpdateAsync(
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            x => x.Id == sensorId,
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            sensorUpdate,
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            new() { ReturnDocument = ReturnDocument.After });
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    if (sensorDetail != null)
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    {
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        var siteUpdate = Builders<SiteOverview>
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            .Update
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            .Set(x => x.Last, measurement);
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        var siteId = sensorDetail.SiteId;
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        await overviewsColl
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            .OfType<SiteOverview>()
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            .UpdateOneAsync(x => x.SiteId == siteId, siteUpdate);
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    }
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}

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var siteOverviews = (await overviewsColl
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        .OfType<SiteOverview>()
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        .FindAsync(FilterDefinition<SiteOverview>.Empty))
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    .ToEnumerable();

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var siteDetails = await (await overviewsColl
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    .FindAsync(x => x.SiteId == siteId))
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    .ToListAsync();