How I Build a MySql plugin for QT5 (Windows, MinGW32)

1. Download MySql C Connector v6.1.

   Download the MySql Installer from:
   https://dev.mysql.com/downloads/installer/
   Install C Connector 6.1 (Note the location we will need it later)

2. Getting QT Source Ready

   To build a plugin for QT u need to get its source. You can install it from Maintenance Tool or manually get it from github repository.

3. Building Plugin

   1. Open MinGW CMD (Windows -> Start Menu -> Programs -> Qt 5.13.1 -> 5.13.1-> MinGW 7.3.0 (32-bit) -> Qt 5.13.1 (MinGW 7.3.0 32-bit) )
   2. cd to sqldrivers path in qt source

   cd D:\\QT\\Qt5.13.1\\5.13.1\\Src\\qtbase\\src\\plugins\\sqldrivers
   

   1. Run qmake here. qmake sqldrivers.pro (to create qtsqldrivers-config.pri )
   2. cd to mysql.

   cd D:\\QT\\Qt5.13.1\\5.13.1\\Src\\qtbase\\src\\plugins\\sqldrivers\\mysql
   

   1. Run qmake here. qmake mysql.pro

4. Add the plugin to the list

   Once successfully build you will find qsqlmysql.dll and qsqlmysqld.dll in
   the following location
   D:\QT\Qt5.13.1\5.13.1\Src\qtbase\src\plugins\sqldrivers\plugins\sqldrivers

   Copy both qsqlmysql.dll and qsqlmysqld.dll and place them in the compiler’s
   plugin directory
   D:\QT\Qt5.13.1\5.13.1\mingw73_32\plugins\sqldrivers

Error in Building?

1. Library 'mysql' is not defined.

   In file cd
   D:\QT\Qt5.13.1\5.13.1\Src\qtbase\src\plugins\sqldrivers\mysql\mysql.pro

   Commend the line QMAKE_USE += mysql

2. Adding Library path and Include path.

   Add the following to mysql.pro at end

   LIBS += -L'C:/Program Files (x86)/MySQL/MySQL Connector C 6.1/lib/'
   -llibmysql
   
   INCLUDEPATH += 'C:/Program Files (x86)/MySQL/MySQL Connector C 6.1/include'
   
   DEPENDPATH += 'C:/Program Files (x86)/MySQL/MySQL Connector C 6.1/include'
   

3. QSqlDatabase: QMYSQL driver not loaded

   Add the .dll files from C:/Program Files (x86)/MySQL/MySQL Connector C 6.1/lib to D:\QT\Qt5.13.1\5.13.1\mingw73_32\bin