How to Enable MySQL Support in Qt SDK for Linux

Updated: 8 May 2012

Known to work with:

• Slackware v13.37, Qt SDK v1.1.5 (32 bit), Qt v4.8.0, MySQL v5.5.18

Please follow this guide properly:

1. Download Qt SDK for Linux/X11 at Qt Software.

2. Install it anywhere you want, just make sure you remember the path. I installed mine at /opt.

3. To build MySQL as a plugin, you need to know two other paths:

   • MySQL header directory’s files example:

     decimal.h   m_string.h      my_dbug.h    my_list.h        my_sys.h     mysql_embed.h    mysqld_error.h  sql_state.h        typelib.h
     errmsg.h    my_alloc.h      my_dir.h     my_net.h         my_xml.h     mysql_time.h     raid.h          sslopt-case.h
     keycache.h  my_attribute.h  my_getopt.h  my_no_pthread.h  mysql.h      mysql_version.h  readline.h      sslopt-longopts.h
     m_ctype.h   my_config.h     my_global.h  my_pthread.h     mysql_com.h  mysqld_ername.h  sql_common.h    sslopt-vars.h

   • MySQL library directory’s files example:

     libdbug.a    libmyisammrg.a      libmysqlclient.so@         libmysqlclient_r.a    libmysqlclient_r.so.15@      libmysys.a
     libheap.a    libmysqlclient.a    libmysqlclient.so.15@      libmysqlclient_r.la*  libmysqlclient_r.so.15.0.0*  libvio.a
     libmyisam.a  libmysqlclient.la*  libmysqlclient.so.15.0.0*  libmysqlclient_r.so@  libmystrings.a

4. I installed my MySQL at /opt, so those files will be in:

   # Headers directory
   /opt/mysql-5.5.18-linux2.6-i686/include/  
   
   # Libraries directory
   /opt/mysql-5.5.18-linux2.6-i686/lib      

5. Go to your main Qt SDK installation’s path:

   cd /opt/QtSDK/
   cd QtSources/4.8.0/src/plugins/sqldrivers
   # Replace all the path based on your computer environment. 
   /opt/QtSDK/Desktop/Qt/4.8.0/gcc/bin/qmake -o Makefile "INCLUDEPATH+=/opt/mysql-5.5.18-linux2.6-i686/include/" "LIBS+=-L/opt/mysql-5.5.18-linux2.6-i686/lib -lmysqlclient" mysql.pro
   make
   /opt/QtSDK/Desktop/Qt/4.8.0/gcc/bin/qmake "INCLUDEPATH+=/opt/mysql-5.5.18-linux2.6-i686/include/" "LIBS+=-L/opt/mysql-5.5.18-linux2.6-i686/lib -lmysqlclient_r" mysql.pro
   make
   make install

6. Some files with mysql in the name will be copied in your sqldrivers path:

   /opt/QtSDK/Desktop/Qt/4.8.0/gcc/plugins/sqldrivers

7. Before trying your MySQL coding, please make sure libmysqlclient.so is in theLD_LIBRARY_PATH.

8. Create a new project and put these codes to test your new plugin.

   QT       += core sql
   QT       -= gui
   
   TARGET    = mysql
   CONFIG   += console
   CONFIG   -= app_bundle
   	
   TEMPLATE = app
   
   SOURCES += main.cpp

   Make sure you have mysql included in your .pro file.

   #include <QCoreApplication>
   #include <QtSql>
   	
   int main(int argc, char *argv[])
   {
       QCoreApplication a(argc, argv);
   
       qDebug() << QSqlDatabase::drivers();
   
       return a.exec();
   }

   You should get QMYSQL in the outputs when you ran the application:

   ("QSQLITE", "QMYSQL3", "QMYSQL")

You can find my info at http://qt-project.org/doc/qt-4.8/sql-driver.html.