nearly 50 years ago

Jenya · Post by **Jenya** » Mon 13 Jul 2009 13:22

deficient in vitamin K, other compounds fill in for these functions. It is the blood-clotting ability that If a death has brought about 3 to 7 days/week 60 to 75%
O man check out the quotes from the whole ordeal: Bruno was heard screaming Aarh! My kugelsack! My kugelsack! as he slowly dropped headfirst towards the Lose Yourself star. He furth
pitulated by visible GFP expression. For HIV-1 Rev protein were tested in a sur- episodes, and seizures. Additional studies
I take it normal zombies and not zombie headcrabs? It would be nice if once in a while there is a huge rush of antlions that attack or a huge blitzkrieg of headcrabs. Well, I was thinking they woul

Challenger · Post by **Challenger** » Wed 15 Jul 2009 11:52

You should set the Username, Password, Server, and Port properties of TMyConnection and call the Connect method.

Jenya · Post by **Jenya** » Thu 03 Sep 2009 12:21

Everything is good until i use incorrent username or password or server. In this case exception rises up (Error message Dialog). But i only want the Boolean value is to be returned. How can i check connection with out error message?

Dimon · Post by **Dimon** » Fri 04 Sep 2009 08:36

You can catch the exception in try..except statement, like this:

Code: Select all

try
  MyConnection.Connect;
except
end;

if MyConnection.Connected then
...

mwilems1 · Post by **mwilems1** » Thu 17 Sep 2009 19:12

Correct. Use exception handling with "try/except" and capture the exception.

To find the exception run without exception handling and look at the exception class, number, and text returned. You can then use any of these to build your exception handler. The class is the easiest using "on [exceptionClass] do".

Here is an excerpt from the MyDacDemo.prj that comes with MyDAC 5.80.0.46:

Code: Select all

procedure TfmCustomConnect.DoConnect;
begin
  FConnectDialog.Connection.Password := edPassword.Text;
  FConnectDialog.Connection.Server := edServer.Text;
  FConnectDialog.Connection.UserName := edUsername.Text;
  (FConnectDialog.Connection as TMyConnection).Port := StrToInt(edPort.Text);
  FConnectDialog.Connection.Database := edDatabase.Text;
  try
    FConnectDialog.Connection.PerformConnect(FRetry);
    ModalResult := mrOk;
  except
    on E: EMyError do begin
      Dec(FRetries);
      FRetry := True;
      if FRetries = 0 then
        ModalResult := mrCancel;
      if E.ErrorCode = CR_CONN_HOST_ERROR then
        ActiveControl := edServer
      else
      if E.ErrorCode = ER_ACCESS_DENIED_ERROR then
        if ActiveControl  edUsername then
          ActiveControl := edPassword;
      raise;
    end
    else
      raise;
  end;
end;

If you notice, in the Except statement they assign E to a type of EMyError and then check the ErrorCode property of EMyError for specific values. I looked in the Help files but could not find the enumeration values for ErrorCode.

Dimon · Post by **Dimon** » Fri 18 Sep 2009 08:26

The ErrorCode property is error code that is received from MySQL server. We don't describe the enumeration of these values because they are defined by MySQL server.

mwilems1 · Post by **mwilems1** » Fri 18 Sep 2009 15:33

Excelent.

That will help me with detecting when my connection has timed out.

I use a database sitting on servers over the Internet. The OnConnectionLost event does not detect the time out of the server. I have not tried to identify what the exact error is. The message I get is "class EMySqlException with message 'Lost connection to MySQL server during query'. WSAGetLastError return 10053."

I can probably use this in the OnError handler with the MySQL enumerations.

Thanks.

eduardosic · Post by **eduardosic** » Fri 18 Sep 2009 18:03

mwilems1 wrote:Excelent.

That will help me with detecting when my connection has timed out.

I use a database sitting on servers over the Internet. The OnConnectionLost event does not detect the time out of the server. I have not tried to identify what the exact error is. The message I get is "class EMySqlException with message 'Lost connection to MySQL server during query'. WSAGetLastError return 10053."

I can probably use this in the OnError handler with the MySQL enumerations.

Thanks.

Hi mwilems1, to avoid LostConnection, if you are using the version 5 of Mydac you can use LocalFailOver, is very useful.

Dimon · Post by **Dimon** » Mon 21 Sep 2009 07:23

mwilems1 wrote:I use a database sitting on servers over the Internet. The OnConnectionLost event does not detect the time out of the server. I have not tried to identify what the exact error is. The message I get is "class EMySqlException with message 'Lost connection to MySQL server during query'. WSAGetLastError return 10053."

This error is arised when socket tries to transmit data by aborted connection.
You can read more about the WSAGetLastError(10053) error in MSDN.