Just wondering does RDBMS like mysql, oracle, sqlserver support using triggers to fire the update events to a message queue?
In PostgreSQL call pg_notify('mychannel', 'my message'); in a trigger
Your message queue, or an intermediary component, would call LISTEN mychannel on a connection to the PostgreSQL database, and send a message to the queue.
Looks like there is an extension to publish directly from PostgreSQL to an AMQP message queue (though not active):
https://github.com/omniti-labs/pg_amqp
If using Oracle use AQ (Advanced Queuing) http://docs.oracle.com/cd/B10501_01/appdev.920/a96587/qintro.htm
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I am new to nodejs and I would like to figure out how I could have event listeners from SQL Server trigger a Nodejs function on my server.
For instance, I would like my Nodejs server to receive notifications when there is any change (insert/update) for any given table in my database, which would then trigger an update of the UI on the client-side.
I'm not altogether familiar with SQL Server, but I don't think you'll want to be using your DB server to POSTs to a webhook endpoint anyhow.
You're better off handling this functionality in your application code rather than on your database server.
The general idea is that it's your application that's going to be operating on the database anyhow, so you should have your application send out the the updates to your UI. A high-level step-by-step would look like so:
Client sends request to server
Server receives request and updates database
Upon a successful update of the database, your server sends a response to the client
The client receives the response from the server and adjusts the UI accordingly
When I do something such as insert, update in SQL Server, and I have a Service Broker queue. I just know do SEND to send the message to the queue.
Q: can the message send to queue automatically? Thanks.
No, there is no built-in way of sending messages in response to changes to a table. You would have to wire this up yourself using triggers or forcing all your table changes to go via stored procedures.
I am building a support ticket system using Sql Server 2014, ASP.Net MVC 5, angular JS etc.
As part of the design I want a way for my system to know when a ticket has been updated, deleted, or created.
That way if a user has a ticket open and it is changed while they have it open I can design the system to force them to refresh the ticket before they themselves can make changes to it, to prevent User B from overriding User A's changes they haven't seen.
Ideally, I'd like to design a TCP Protocol server as a Windows Service and be able to connect to it and send it data from table triggers in Sql Server.
Then the application front end would use Javascript and WebSockets. So the application would be connected to the socket server as well as sql server. When a user opens a ticket I would send a message that user XXY has Ticket 00X open. When a change happens in sql server it tells the server Ticket 00X changed. Then the Socket server tells clients connected to it that are looking at Ticket 00X that it has changed and the javascript prevents a submit until a fresh is done.
But... Can sql server do this at all? Doesn't appear so.
So I'm wondering if it's posisble to build a plugin for SQL Server to enable support for it like PostgreSQL's Notify feature.
Update:
I've discovered User Defined CLR Functions in SQL Server and have managed to get it working. (C#/.Net Framework) I made a static class with some static methods like,
public static int NotifyTicketUpdate(int ticketID)
{
//...
}
Then I registered it in SQL Server,
USE TLCDB;
CREATE ASSEMBLY MyCompanyName_MyDll
FROM 'd:\pathtodll\mydll.dll'
WITH PERMISSION_SET = SAFE;
CREATE FUNCTION XYZ_Notify_Ticket_Updated(#input int) RETURNS int
AS EXTERNAL NAME MyCompanyName_MyDll.UserDefinedFunctions.NotifyTicketUpdated;
Then to call it in SQL, I just do
select dbo.XYZ_Notify_Ticket_Updated(#ticketIDHere);
And it all works. My Static method in c# sends the TCP/IP message to my socket server, the server then checks to see who is looking at that ticket ID and sends them a Ticket_Updated message. The websocket layer running in client javascript sees it, and locks the ticket for updates/saves.
Or you can use Service Broker for handling asynchronous notifications. Not the simplest thing to learn, but lightweight, scalable and already built-in.
You could use CLR, which requires a bit of setup.
You could create an EXE that you can shell with parameters from an SP.
You could implement some standard concurrency. Optimistic vs Pessimistic
So yes, it's possible.
I'm trying to figure out the easiest way to send SQL Server Event Notifications to a separate server using service broker. I've built an endpoint on each server, a queue on each server, working on Dialogs and Contracts and activation... but do I need any of that?
CREATE EVENT NOTIFICATION says it can send the notification XML to a "target service" - so could I just create a contract on the "sending" server that points to a queue on a "receiving server", and use activation there?
Or do I need to have it send to a local queue and then forward on to the receiving server's queue? Thanks!
You can target the remote service, but you have to have the ROUTEs defined for bidirectional communication so that you get the Acknowledgement message back. I once had a script for creating a centralized processing server for all Event Notifications, and the other servers targeted it's service. If I can find it I'll post it on my blog and update this with a link.
I am new to Sql Server Service Broker and experimenting with it.
I was able to send messages from one DB and receive those messages in another DB (of the same SQL server) and I am inserting those messages into a table in the receiving DB.
Everything is working so far, but everytime I send a message from the source DB, I have to go the destination DB and run the RECEIVE query manually to fetch the message from the receiving queue and insert into the table.
I would like to automatically receive the messages from the receive queue as soon as they arrive (or in a schedule, say every 10 minutes) and insert them into my destination table, without me manually doing it.
One option is to create a SP and schedule that to run every 10 minutes. I am not sure if that is the recommended way or if there is any other better way to listen to the receiving queue and automatically retrieve the messages as soon as they arrive.
Any help would be appreciated.
What you're looking for is what's called broker activation (specifically, internal activation). In essence, you can "attach" a stored procedure to a service broker queue that will be called when a message shows up on the queue. Read all about it in BOL.