C# MongoDB driver: unique index

Question

I have a model with _id, name and other fields. I want to create an index so it would be impossible to save documents with same names. I'm creating an index such way:

public static async Task EnsureIndexExists(this IMongoDatabase database, string collectionName, string indexName)
        {
            var collection = database.GetCollection<BsonDocument>(collectionName);
            var builder = Builders<BsonDocument>.IndexKeys;
            var field = new StringFieldDefinition<BsonDocument>(indexName.FromPascalToCamel());
            var indexModel = new CreateIndexModel<BsonDocument>(builder.Ascending(field));
            await collection.Indexes.CreateOneAsync(indexModel).ConfigureAwait(false);
        }

// ...

database.EnsureIndexExists(CharacterRepository.CollectionName, nameof(CharacterEntity.Name)).Wait();

The model:

public class CharacterEntity
    {
        [BsonId]
        [BsonRepresentation(BsonType.ObjectId)]
        public string Id { get; set; }
        public string Name { get; set; }
        //...
    }

But still documents with the same names can be saved into DB.

The driver versions:

<PackageReference Include="AspNetCore.Identity.MongoDbCore" Version="2.1.1" />
<PackageReference Include="MongoDB.Driver" Version="2.11.1" />

What I'm doing wrong?

Nikita Fedorov · Accepted Answer · 2020-09-27 11:59:00Z

2

I just had to add CreateIndexOptions:

public static async Task EnsureIndexExists(this IMongoDatabase database, string collectionName, string indexName)
        {
            var collection = database.GetCollection<BsonDocument>(collectionName);
            indexName = indexName.FromPascalToCamel();

            var index = new BsonDocument
            {
                {indexName, 1}
            };

            var indexModel = new CreateIndexModel<BsonDocument>(index, new CreateIndexOptions { Unique = true });
            await collection.Indexes.CreateOneAsync(indexModel).ConfigureAwait(false);
        }

answered Sep 27, 2020 at 11:59

Nikita Fedorov

9702 gold badges18 silver badges44 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

C# MongoDB driver: unique index

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related