MYSQL & MT5: creating a mysql driver for mt5

[Christian Stern]

Hey all,

i had the plan to use MT5 with mysql but looks like it turns into more work as expected. There is a howto from Eugeniy ( https://www.mql5.com/en/articles/932 ) which explains it very well. But when you try to load his MQLMYSQL.dll it fails because it is not a x64 binary.

My plan is now to migrate this sources to latest mysql 6.1 connector and MT5 x64 support.

So, thats not the problem because he attached his Visual Studio Project and we can compile it for x64. I compiled it with Visual Studio 2017, no problmes so far.

And now here is the "but". Somehow MT5 has Problems with wchar_t variable/function types. I reduced the troubleshooting down to this point:

// return version of MT5 MySQL Version
MT5_API wchar_t* __stdcall cMySqlVersion()
{
    return (L"MT5 MySQL v1.0 ");
}

When i use another return type, then the dll will be loaded.

Does someone has a clue how to solve this problem ? Attached you can find my modified project.

Thanks in advanced

[trader4321]

Christian Stern:

Hey all,

i had the plan to use MT5 with mysql but looks like it turns into more work as expected. There is a howto from Eugeniy ( https://www.mql5.com/en/articles/932 ) which explains it very well. But when you try to load his MQLMYSQL.dll it fails because it is not a x64 binary.

My plan is now to migrate this sources to latest mysql 6.1 connector and MT5 x64 support.

So, thats not the problem because he attached his Visual Studio Project and we can compile it for x64. I compiled it with Visual Studio 2017, no problmes so far.

And now here is the "but". Somehow MT5 has Problems with wchar_t variable/function types. I reduced the troubleshooting down to this point:

// return version of MT5 MySQL Version
MT5_API wchar_t* __stdcall cMySqlVersion()
{
    return (L"MT5 MySQL v1.0 ");
}

When i use another return type, then the dll will be loaded.

Does someone has a clue how to solve this problem ? Attached you can find my modified project.

Thanks in advanced

Hi,

Did you mange to fix the issue? Do you have a working version now?

Thank in advance