I have a qt app with a mysql backend. I want the app to get updated whenever the database changes, as I'm planning on having other methods to change the db.
I've successfully installed the lib_mysqludf_sys UDF which allows mysql triggers to run commands via sys_exec or sys_eval. I was hoping to have the sql trigger run a small program which would connect to my main qt app over a d-bus session to force an update in the app without having to do a bunch of polling.
When I try and connect to the d-bus session I get the following error:
Cannot connect to the D-Bus session bus.

I also get an error about connecting to display:0, and I've somewhat worked around that by running: xhost +local:mysql

I figured I'd post something since I've been stuck on this for a couple days now, but I have found the following, which seems like it might be on the right track:
http://unix.stackexchange.com/questi...the-session-id

Thanks.

I haven't the faintest clue but that never stopped me from asking questions ;-p
- What's your OS and release?
- Can you run any of the example UDFs like touching a file?
- Does dbus run?
- Do you get the right dbus session?
- Can you perform any other action within that right dbus session, say a dbus-launch?
- What's the actual dbus command you're trying to trigger with the UDF?
- Do you know how to run dbus and that trigger in debug mode?

Thanks for the reply! Here

- What's your OS and release?
I'm using debian, kernel 3.16.0-4

- Can you run any of the example UDFs like touching a file?
Yes, I've successfully run 'touch /tmp/blah.txt', and stuff like 'pwd' and 'whoami'

- Does dbus run?
It's running fine when I just launch my Qt app using a non-mysql user. I can run the app which establishes the dbus session, then run it again with a parameter to signal a message to the first instance and it works fine.

- Do you get the right dbus session?
When I run it as mysql (just creating a bash session using mysql or using the UDF) it doesnt connect to dbus at all.

- Can you perform any other action within that right dbus session, say a dbus-launch?
dbus-launch was having issues, will try that some more. I was previously using my qt app.

- What's the actual dbus command you're trying to trigger with the UDF?
I'm trying to run the qt app, but going to try and use dbus-launch.

- Do you know how to run dbus and that trigger in debug mode?
No, I'll look into it.

I was able to see the everything and run the methods using dbus-send and d-feet using my normal user account.
When I use the mysql account, d-feet is able to load the system bus but not the session bus.

I'll see if I can switch it to use the system bus.

Switching to a system bus seems to be working. Thanks!

Thanks for posting your solution.
Please mark thread solved.