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Hello All!

We are planning to change our XP-workstations to Windows 7 at some point and while testing the compatibility for our delphi-created applications we found problems.

The client application installed on Windows 7 workstation gives error "Can't connect to MySQL server on 'server' (10061)"

A client on the same network, but using Windows XP is working ok.

I have disabled the windows firewall on win7, running the application as administrator but nothing seems to help. In addition, I installed the mysql query browser to the win7 and that works&connects with no issues.

Are there any known compatibility issues with MyDAC and Win7?


Some background information:
Client1:
Nokia Booklet 3G
Win7 Starter

Client2 (aka developer machine):
WinXP
Delphi 2005
MySQL Data Access Components 3.55.26 for Delphi 2005

Server:
Intel XEON E5520/6GB RAM
Windows Server 2008 R2
MySQL server 4.1.22

Ok, there are many things above that can be regarded as antique, but they have worked fine so far

Kind regards,
Kalle Anttila

I use MyDac in my Application in Windows XP/Vista/ and 7.
work very well.

look if the computer with windows 7 have access to database server.
try ping.. by name, by ip address, try a mysql GUI like, EMS or MySQL Administrator.

In former time, my developer machine is XP + Delphi 7 + MyDAC 5.X. The program it compile can run on Win 7 with no problem.

As you had installed MySQL Query Browser and can connect to MySQL well, the most possible reason is MyDAC 3.x not compatible to Win 7.

You might try to disable TMyConnection.Options.Direct so that it use LibMySQL.dll to connect.

Justmade wrote:You might try to disable TMyConnection.Options.Direct so that it use LibMySQL.dll to connect.

Thanks for the tip!

I tried this with my small test application and it solved the issue nicely! However I do not understand the difference between the true and false values. I am just wondering that would it be better to use value true for the XP machines that can work with the setting? this is quite easy to do by adding "Win7 compability mode" selection to the program so that different OS:s can use different settings.

It also seems I have another issue with win7; For some reason I am unable to connect to the SQL server thru openVPN client... This works nicely with XP, but the same settings with win7 do not work, even if the remote connection does. But then again, here the MySQL Admin and my own application work in the same way, so this issue is most likely somewhere outside the MyDAC.

It might be also a good idea to upgrade to mydac 5, but I am not sure if I should go to UniDAC instead...

The direct mode is a key technology of MyDAC that let MyDAC components to directly connect to MySQL server without using the MySQL client library (libmysql.dll) which provide and faster and more effecient connection.

So, if speed is important to your application, using direct mode is surely an advantage.

no problem in compatibilities ...
all works fine ..