Discussion of article "How to Access the MySQL Database from MQL5 (MQL4)" - page 3

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Ingvar Engelbrecht
4408
Ingvar Engelbrecht  
elugovoy:

I'm working on this issue with service desk, hope to hear from any good news soon.

Regarding TICK_VALUE, I've had the same troubles too even in MT4. Here is workaround I'm using:

 or

  I will try it  :-)

 Did not work. Stuck in loop.

Ingvar Engelbrecht
4408
Ingvar Engelbrecht  

I got an idea on the tick value problem. I am running a multicurrency EA and I start out  getting a lot of info for each pair. So it gets a bit like "hammering". I will change that so

that the tickvalue will only be asked for when needed. (and saved)

-   Updated  --

Not completely in the green. Have made the change above. Optimization still works. No error messages when starting EA.  OK will be when the EA has taken a trade ok. Have to wait.

This is running a 32 bit version of the EA in a Windows 7 64 bit environment. It will at least temporarely solve the problem if it works.

I only fetch the Tickvalue when the first order is on its way and save it.

Ingvar Engelbrecht
4408
Ingvar Engelbrecht  

OK, running an install of 32-version by appending "/32" to the MT5 installer works fine on a windows 7 64 bit computer and the mysql tool also works fine.

Back to basic design problems and testing with the EA,

Eugeniy Lugovoy
1960
Eugeniy Lugovoy  
ingvar_e:

OK, running an install of 32-version by appending "/32" to the MT5 installer works fine on a windows 7 64 bit computer and the mysql tool also works fine.

Back to basic design problems and testing with the EA,

Hello Ingvar,

The MetaQuotes service desk promised to fix it in next MT5 build.

So, we only have to wait release of next MT5 build.

 

Thanks 

Ingvar Engelbrecht
4408
Ingvar Engelbrecht  
elugovoy:

Hello Ingvar,

The MetaQuotes service desk promised to fix it in next MT5 build.

So, we only have to wait release of next MT5 build.

 

Thanks 

   Thanks for information elugovoy. In the meantime i run a 32 bit version. Installing with option /32. works fine.

  Nice piece of SW. Storing tradeparameters with a script from file and retrieve them in the EA. MySQL runs on my server so I

can retrieve parameters both on  EA running on another server and on local developing computers.

Ingvar Engelbrecht
4408
Ingvar Engelbrecht  

Hi again.

New build 1060 out. Have you tested if they fixd it? 

Eugeniy Lugovoy
1960
Eugeniy Lugovoy  
ingvar_e:

Hi again.

New build 1060 out. Have you tested if they fixd it? 

Yeah, it is worked fine now (have tested build 1062)
Ingvar Engelbrecht
4408
Ingvar Engelbrecht  

OK, I have tested 1060 now and it works ok too

Good, simplifies my testing. Get rid of 32-bits 

illman
9
illman  

Hello sir ,my MT4 show :Connection failed! Error: Maximum connections exceeded.——how can I deal with this problem? I guess the Maximum connections are 32,how can I raise the connections to such as 64 ?

thanks for helping,sir.

Eugeniy Lugovoy
1960
Eugeniy Lugovoy  
illman:

Hello sir ,my MT4 show :Connection failed! Error: Maximum connections exceeded.——how can I deal with this problem? I guess the Maximum connections are 32,how can I raise the connections to such as 64 ?

thanks for helping,sir.

Hello,

Yes the max number of connections is 32 

Are you trying to use your MQL program based on MQLMySQL.dll on more than 32 charts concurrently?

Or you just forgot to close the connection in your program? 

To change max connection from 32 to another you have to rebuild MQLMySQL.DLL. The sources are attached to the article, you have to:

1. Unpack sources from "MQLMySQL DLL Project MSVS-2010.zip"

2. Load the project into MS Visual Studio 2010 or higher

3. Open file "MQLMySQL.h"

4. Find string:

// database definition
#define MAX_CONNECTIONS 32

and replace value 32 with 64 or whatever you want

// database definition
#define MAX_CONNECTIONS 64

5. Rebuild the project

6. Replace an old DLL in your Metatrader data folder with new compiled.

Regards,

Eugene 

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