Cannot await a .find method using mongodb c#

July 12, 2022

I am a novice so I apologize but I keep getting this CS1061 error when trying to await a .find() method. How do I await this find()?

MongoClient client = new MongoClient(mongoDBSettings.Value.ConnectionURI);
        IMongoDatabase database = client.GetDatabase(mongoDBSettings.Value.DatabaseName);
        _userCollection = database.GetCollection<User>(mongoDBSettings.Value.CollectionName);
        _partyCollection = database.GetCollection<Party>(mongoDBSettings.Value.CollectionName);

public async Task<IEnumerable> GetNearbyParties(string postalCode)
{

        var nearbyParties = await _partyCollection.Find(x => x.Address.postalCode == postalCode);

        return (IEnumerable<Party>)nearbyParties;

    }

MongoClient client = new MongoClient(mongoDBSettings.Value.ConnectionURI);
IMongoDatabase database = client.GetDatabase(mongoDBSettings.Value.DatabaseName);
_userCollection = database.GetCollection(mongoDBSettings.Value.CollectionName);
_partyCollection = database.GetCollection(mongoDBSettings.Value.CollectionName);

public async Task<IEnumerable> GetNearbyParties(string postalCode)
{

        var nearbyParties = await _partyCollection.Find(x => x.Address.postalCode == postalCode);

        return (IEnumerable<Party>)nearbyParties;

    }

I had it originally set up like this running synchronously:
public async Task<IEnumerable> GetNearbyParties(string postalCode)
{

        var nearbyParties = _partyCollection.Find(x => x.Address.postalCode == postalCode);

        return (IEnumerable<Party>)nearbyParties;

      
      



        //return results;
    }

But I understand that since it’s an async method I should have an await when I try to search the database so that other things can run while that is fetched.

>Solution :

You need to call asynchronous API of Mongo not normal Find method:

public async Task<IEnumerable> GetNearbyParties(string postalCode) {
    
            var nearbyParties = await _partyCollection.FindAsync(x => x.Address.postalCode == postalCode);
    
            return (IEnumerable<Party>)nearbyParties;
    
        }