SignalR SQL Notification

Kmcnet 706

Hello everyone and thanks for the help in advance. I am refactoring an application to .Net 5 SignalR that utilizes SQL Notification. The application is partially working, sending a notification to the client on the first time the page loads. However, subsequent database updates fire the OnChange event handler, but doesn't send the update back to the client.

On the initial page load, the client notification fires correctly. However, each ensuing database change fails to return anything to the client, even though the email notifications send correctly each time the database. I see no errors in the console, so I am not sure what is going wrong. Any help would be appreciated.

Yinqiu Yao-MSFT 236 Reputation points

2021-06-21T01:09:00.883+00:00

Hi @Kmcnet ,Please describe your problem in detail with your code, which will better help us understand your problem and solve it.
Kmcnet 706 Reputation points

2021-06-21T19:32:17.087+00:00

II am trying to post code, but each time am receiving the following:

Access Denied
You don't have permission to access "http://learn.microsoft.com/answers/answers/441414/post.html" on this server.
Reference #18.ed11cb8.1624303844.bc70ac1

I posted this problem to the Q and A tag, but haven't heard back/
Kmcnet 706 Reputation points

2021-06-21T21:16:12.237+00:00

107668-codesample.txt

In the meantime, I uploaded a txt document with the code sample.
Yinqiu Yao-MSFT 236 Reputation points

2021-06-22T01:37:31.47+00:00

Hi @Kmcnet ,First check your console to check whether your result has a value, and then try Reconnect clients.
Kmcnet 706 Reputation points

2021-06-22T02:02:59.01+00:00

Thanks for the response. The console does not return anything.
Yinqiu Yao-MSFT 236 Reputation points

2021-06-22T02:36:17.533+00:00

Try to change your signalR.HubConnectionBuilder().withUrl("/CallNotificationHub") to signalR.HubConnectionBuilder().withUrl("https://myappurl/CallNotificationHub")
Kmcnet 706 Reputation points

2021-06-22T19:43:48.017+00:00

Thank you for the response. I did try changing the url without success. I need to also be a little more clear in my description. On the first page load, an alert is sent to the client and the result is written to the console. This suggests the url is correct. However, when a database change occurs, nothing is sent to the client. However, the email notification in both the SendCallNotifications part of the hub as well as the dependency_OnChange fire correctly and send the email notification each time a database change occurs, so this seems to eliminate a SQL notification problem (yes, I have confirmed the Service Broker is working and also have an older version of the application running correctly on the same machine monitoring the same database table. So, in my mind, I have ruled out a pure SQL notification problem. So I am really stumped on this problem. Perhaps the dependency_Change not being a task?
Yinqiu Yao-MSFT 236 Reputation points

2021-06-23T06:11:45.82+00:00

Hi @Kmcnet ,Can you provide your onchange fuction?
Kmcnet 706 Reputation points

2021-06-23T23:34:37.9+00:00

dependency_OnChange is included in the 107668-codesample.txt file I uploaded earlier in this thread.
Yinqiu Yao-MSFT 236 Reputation points

2021-06-24T01:51:16.937+00:00

Debug your code if (e.Type == SqlNotificationType.Change) to check whether to enter the if condition.
Kmcnet 706 Reputation points

2021-06-24T20:55:30.213+00:00

I removed the if (e.Type == SqlNotificationType.Change) condition altogether and it did not make a difference.
Kmcnet 706 Reputation points

2021-06-29T01:50:05.697+00:00

Any other ideas? I've been working on this for weeks and can't get it working. By any chance, have you tried my code in your environment and did it work? Can you point me to a working example that uses SQL Notification?

Share via

SignalR SQL Notification