Devart Forums

On the website, it claims that it has database change notification support?

Can you give an example of how to set this up?

Well, the algorithm is actually very simple.
Here are your steps:
- rise a notification on the server side (see MySQL server documentation);
- choose in Visual Studio Forms designer your connection;
- look at Properties Window, click on the Events button;
- now you will see Error, InfoMessage and StateChange events;
- simply subscribe to the InfoMessage event;

Thats where I got confused, I've read that Mysql doesn't have notification messages. Apparenlty this is incorrect?

I see the event under the connection object (InfoMessage event), but could you please link me the mysql documentation that says how to setup server side events?

I have been searching all MySQL server documentation and
didn't find any scent of raising notifications on the server side.
Unfortunately, the server doesn't support this feature.

Alright, so bascially it supports change notification but it doesn't really matter since mysql doesn't support it.

Hope this helps others who think mysql supports change notification.

What notification would you like to receive (please explain the logic)?
What kind of projects do you develop?
Probably we could find an alternative way to solve this problem.

Alexey.mdr wrote:What notification would you like to receive (please explain the logic)?
What kind of projects do you develop?
Probably we could find an alternative way to solve this problem.

We use typed datasets with windows forms. There really isn't an easy way to refresh the data in the dataset when updates are made to the database. Easiest way to update the data is simply poll the database for the changes.

I am guessing that this doesn't scale very well and is the reason while polling is the acceptable method?

Probably you can use CoreLab.MySql.Web.MySqlCacheDependency class.
It represents a process that periodically polls the server and fires an event
if it detects changes in monitored tables.
Please refer to the documentation for the example.

Alexey.mdr wrote:Probably you can use CoreLab.MySql.Web.MySqlCacheDependency class.
It represents a process that periodically polls the server and fires an event
if it detects changes in monitored tables.
Please refer to the documentation for the example.

I'm sorry, I've looked around for the documentation and haven't been able to find anything. I've also looked for the example, but haven't seem to come have found it.

Could you give me more information on where this example is?

I've been looking at the docs here:

http://www.crlab.com/mysqlnet/docs/

I see that this component is intended for web forms, does it work for winforms as well?

You can find help on MySqlDependency class in your local MyDirect .NET help.
It's faster to find it using Index search.

The example of MySqlDependency class usage you can find in
WinForms sample project here:
%Program Files%CoreLab\MyDirect.NET2\Samples\WinForms\

P.S. I have misspelled the class name in the previous post.

Alexey.mdr wrote:
P.S. I have misspelled the class name in the previous post.

That was the problem.

Let me work with this component today and I'll post feed back.

Waiting for your reply.
Hope the problem will be solved.

Alexey.mdr wrote:Waiting for your reply.
Hope the problem will be solved.

This seems to work pretty well and is very easy to setup. So yes, I'd say this look like it'll work for polling the database. Thanks for putting my attention to this component.

We are glad that everything is ok now.
Feel free to contact us if you encounter any problem with MyDirect .NET