« Mongodb and csharp » : différence entre les versions
De Banane Atomic
Aller à la navigationAller à la recherche
(→Errors) |
(→Filter) |
||
| Ligne 16 : | Ligne 16 : | ||
<kode lang='cs'> | <kode lang='cs'> | ||
var builder = Builders<MyClass>.Filter; | var builder = Builders<MyClass>.Filter; | ||
FilterDefinition<MyClass> filter = | FilterDefinition<MyClass> filter = builder.Empty; | ||
filter &= builder.Exists(x => x.Property1); | |||
filter &= builder.Eq(x => x.Property1, "id"); | 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 | filter &= builder.In(x => x.Property1, new[] { "id1", "id2" }); // filter by Property1 equals to one of the ids | ||
Version du 8 mai 2024 à 13:44
Links
- Using LINQ to Query MongoDB in a .NET Core Application
- Create a RESTful API with .NET Core and MongoDB
- Joining Collections in MongoDB with .NET Core and an Aggregation Pipeline
- C# and MongoDB
Access to a collection
|
var mongoClient = new MongoClient("MONGODB_CONNECTION_STRING");
var database = mongoClient.GetDatabase("DB_NAME");
var collection = database.GetCollection<Collection>("COLLECTION_NAME");
|
Filter
|
|
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.FindAsync(filter)).ToList();
|
Pipeline
|
|
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("$sort", new BsonDocument("timestamp", 1));
|
Log
|
|
var mongoUrl = new MongoUrl("MONGODB_CONNECTION_STRING");
var mongoClientSettings = MongoClientSettings.FromUrl(mongoUrl);
mongoClientSettings.ClusterConfigurator = cb =>
{
cb.Subscribe<CommandStartedEvent>(e =>
{
logger.LogTrace($"{e.CommandName} - {e.Command.ToJson()}");
});
};
this.mongoClient = new MongoClient(mongoClientSettings);
|
Configure the Log so it will be displayed in Visual Studio Output Debug window.
Errors
Requested value '_id' was not found
|
|
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();
|
Serializer for MyClass does not represent members as fields
Unable to deserialize a document into a Dictionary.
|
|
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();
|
