André

此外,如果需要限制分组,可以使用:

db.events.aggregate( 
    {$match: {province: "ON"}},
    {$group: {_id: "$date", number: {$sum: 1}}}  
)

Capabilities = new Symbol[] { new Symbol("queue") }

public async Task TestHelloWorld()
        {
            //strange, works using regular activeMQ and the amqp test broker from here: http://azure.github.io/amqpnetlite/articles/hello_amqp.html
            //but this does not work in ActiveMQ Artemis
            Address address = new Address("amqp://guest:guest@localhost:5672");
            Connection connection = await Connection.Factory.CreateAsync(address);
            Session session = new Session(connection);

            Message message = new Message("Hello AMQP");

            Target target = new Target
            {
                Address = "q1",
                Capabilities = new Symbol[] { new Symbol("queue") }
            };

            SenderLink sender = new SenderLink(session, "sender-link", target, null);
            sender.Send(message);

            Source source = new Source
            {
                Address = "q1",
                Capabilities = new Symbol[] { new Symbol("queue") }
            };

            ReceiverLink receiver = new ReceiverLink(session, "receiver-link", source, null);
            message = await receiver.ReceiveAsync();
            receiver.Accept(message);

            await sender.CloseAsync();
            await receiver.CloseAsync();
            await session.CloseAsync();
            await connection.CloseAsync();
        }