Why QMYSQL driver not loaded in QT5.2?

Question

My program is write with QT5.2 and use mysql. I heared that QT5.2 contains MYSQL driver already. However, when I compile and run my program, it is compiled successfully but runned failed with error:

   QSqlDatabase: QMYSQL driver not loaded
   QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QODBC QODBC3 QPSQL QPSQL7

My programe is like this:

     QSqlDatabase db=QSqlDatabase::addDatabase("QMYSQL");
     db.setHostName("localhost");
     db.setDatabaseName("tradingsystem");
     db.setUserName("root");
     db.setPassword("");
     if(!db.open())
     {
          //.....;
     }

And in .pro I add this:

    QT += sql

Mysql is provided by XAMPP.My OS is win7-x64-sp1-ultimate, and XAMPP Version 1.8.2.System Path is as follow:

    C:\Program Files (x86)\SepanderSoft;
    C:\Program Files (x86)\Intel\iCLS Client\;
    C:\Program Files\Intel\iCLS Client\;%SystemRoot%\system32;%SystemRoot%;%SystemRoot%\System32\Wbem;%SYSTEMROOT%\System32\WindowsPowerShell\v1.0\;
    C:\Program Files\Intel\Intel(R) Management Engine Components\DAL;
    C:\Program Files\Intel\Intel(R) Management Engine Components\IPT;
    C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\DAL;
    C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\IPT;
    C:\Program Files\Intel\WiFi\bin\;
    C:\Program Files\Common Files\Intel\WirelessCommon\;
    C:\Program Files (x86)\Intel\OpenCL SDK\3.0\bin\x86;
    C:\Program Files (x86)\Intel\OpenCL SDK\3.0\bin\x64;
    C:\Program Files\Microsoft\Web Platform Installer\;
    C:\Program Files (x86)\Microsoft ASP.NET\ASP.NET Web Pages\v1.0\;
    C:\Program Files (x86)\Windows Kits\8.0\Windows Performance Toolkit\;
    C:\Program Files\Microsoft SQL Server\110\Tools\Binn\;
    D:\Software\MySQL\MySQL Enterprise Backup 3.8.2\

XAMPP location is :

    D:\XAMPP

QT location is:

    D:\Software\Qt

I have installed mysql server-5.6-64bit in D:\Software\MySQL, and when it conflicted with mysql in XAMPP, I uninstalled mysql server-5.6-64bit.

Answer 1

I met with the same error and fixed it successfully by copying file

C:\Program Files (x86)\MySQL\MySQL Connector.C 6.1\lib\libmysql.dll

into to

C:\Qt\Qt5.3.1\5.3\mingw482_32\bin

Youtube link

Answer 2

I also spent about 2 days on this problem, here's how I solved it:

My setup: 64 bit Windows 10 QT 5.11.1 and QT Creator 4.7.1 32 bit Building a 64 bit app...

Download this zip file: mysql-connector-c-6.1.11-winx64.zip from this website: https://downloads.mysql.com/archives/c-c/

copy this file: C:..\mysql-connector-c-6.1.11-winx64.zip\mysql-connector-c-6.1.11-winx64\lib\libmysql.dll

into this directory: C:\Qt\5.11.1\msvc2015_64\bin

Note: change 'msvc2015_64' to whatever compiler you are using, though it needs to be 64 bit.

when deploying your app, copy libmysql.dll to the same directory as your .exe file I hope this helps you same some time and frustration!

Answer 3

I was facing the same issue and even "Hồ Sĩ Sơn"s solution didn't work. I then found out that I had installed a 64-bit version of MySQL and was trying it on a 32-bit version of Qt.

Copying the dll from the below location didn't work:

C:\Program Files\MySQL\MySQL Connector.C 6.1\lib\libmysql.dll

Instead download the 32-bit version of libmysql.dll from:

https://dev.mysql.com/downloads/connector/c/

and the copy it to your mingw folder.

In my case, I had to copy the DLL to msvc2010 folder since I am using Visual Studio compiler:

C:\Qt\5.4\msvc2010_opengl\bin

Hope this helps. :)

Answer 4

Adding post due to reputation deficit.

I was able to resolve my issue using a combination of Hồ Sĩ Sơn, Ram, and Sumanth's posts (Thank you both).

Here are my exact steps:

Checked the version of Qt Creator that I am running by visiting Help -> About Qt Creator. I found that I am running the 32-bit version.

Now that I know what version I am running I navigated to the 32-bit version of the MySQL connector. This was found in C:\Program Files (x86)\MySQL\MySQL Connector C 6.1\lib.

I copied the libmysql.dll file found in that folder, and pasted it into C:\Qt\5.9.2\mingw53_32\bin\ since I am compiling with MinGW. Note that this is the 32-bit folder.

Restarted Qt Creator and rebuilt my project.

The steps that were challenging me were matching the x-bit version of Qt Creator, my compiler, and the driver, then restarting Qt Creator.

Hope this helps someone out there!

Answer 5

I faced the same issue and resolved by below steps.

By doing 6 hours of research finally issue is resolved. I was using 64 bit windows 10, 32 bit Qta and 64 bit MySQL server.

QSQLITE and QODBC was working perfectly, but faced issue with QMYSQL.

Later I have downloaded "mysql-connector-c-6.1.11-win32.zip" (if it is 32 bit QT)from https://dev.mysql.com/downloads/connector/c/ copied "libmysql.dll" to QT path C:\Qt\5.9.3\mingw53_32\bin.

Wow.. it was working perfectly.