QMYSQL driver not loaded on Ubuntu

[A Former User]

I don't understand ! I,m new on Qt ...
Of course I use XAMPP for testing MySQL Database.

my code for test on console app :

@
#include <QCoreApplication>
#include <QtSql/QSqlDatabase>
#include <QtSql>
#include <QDebug>

//remplacer l'affichage par la commande cout
#define q2c(string) string.toStdString()

int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);

QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL"); // This is the line I got error
   db.setHostName("localhost");
   db.setDatabaseName("qtdatabase");
   db.setUserName("root");
   db.setPassword("");
   bool ok = db.open();

return a.exec();

}

@

return this errors :

QSqlDatabase: QMYSQL driver not loaded
QSqlDatabase: available drivers: QSQLITE QSQLITE2 QMYSQL QMYSQL3 QPSQL7 QPSQL

but with this code :

@
#include <QCoreApplication>
#include <QtSql/qsql.h>
#include <QtSql/qsqldatabase.h>
#include <QtSql/QSqlError>
#include <QtSql/QSqlQuery>
#include <QDebug>

int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);

QStringList drivers = QSqlDatabase::drivers();
    for(int i = 0; i < drivers.count(); i++)
        qDebug() << drivers.at(i);

return a.exec(&#41;;

}

@

return this output:

"QMYSQL","QMYSQL3" and ...

[SGaist]

Qt's MySql plugin is call libqsqlmysql.so, call ldd on it and check that it can find all dependencies

[A Former User]

[quote author="SGaist" date="1388524196"]Qt's MySql plugin is call libqsqlmysql.so, call ldd on it and check that it can find all dependencies[/quote]

what is your mean of ldd ? I have libqsqlmysql.so file in below address :

/opt/Qt5.2.0/5.2.0/gcc_64/plugins/sqldrivers

[SGaist]

ldd is a little utility that lists the dependencies of an executable/dynamic library

[A Former User]

[quote author="SGaist" date="1388526680"]ldd is a little utility that lists the dependencies of an executable/dynamic library[/quote]

How can I check this option ? This is installed utility on OS or Qt ?
Please give me more information about this.
How to call ldd?

I now install Qt on Windows for check my problem but now show error for load..

Qt_5_2_0_MinGW_32bit edition:

Starting C:\Users\Kambiz\Documents\Qt\build-untitled16-Desktop_Qt_5_2_0_MinGW_32bit-Debug\debug\untitled16.exe...
QSqlDatabase: QMYSQL driver not loaded
QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QODBC QODBC3 QPSQL QPSQL7
C:\Users\Kambiz\Documents\Qt\build-untitled16-Desktop_Qt_5_2_0_MinGW_32bit-Debug\debug\untitled16.exe exited with code 0

Qt_5_2_0_MSVC2012_64bit edition:
Starting C:\Users\Kambiz\Documents\Qt\build-untitled15-Desktop_Qt_5_2_0_MSVC2012_64bit-Debug\debug\untitled15.exe...
QSqlDatabase: QMYSQL driver not loaded

[SGaist]

"here":http://bit.ly/1l2bNYY

Did you install MySQL on Windows ? Do you have the MySql dll somewhere accessible in your PATH ?

[A Former User]

[quote author="SGaist" date="1388613736"]"here":http://bit.ly/1l2bNYY

Did you install MySQL on Windows ? Do you have the MySql dll somewhere accessible in your PATH ?[/quote]

Yes I have it on below path :

C:\Program Files\MySQL\MySQL Server 5.6
and
C:\Program Files (X86) \MySQL\MySQL Server 5.6

and on Linux ubuntu too

On Windows I use of qt-windows-opensource-5.2.0-mingw48_opengl-x86-offline.exe and qt-windows-opensource-5.2.0-msvc2012-x86_64-offline.exe

but I don't know why doesn't work :(

[SGaist]

You didn't answer the questions:
What does ldd return ?

Is the MySql dll folder in your PATH variable ? Or at least in the PATH environment variable in the run section of the Project panel in Qt Creator ?

[A Former User]

For Windows...

MySql dll folder :
I have libmysql.dll and libmysql.lib and mysqlclient.lib here C:\Program Files\MySQL\MySQL Server 5.6\lib

and I have qsqlmysql.dll and qsqlmysqld.dll and other files in here :

C:\Qt\Qt5.2.0-MG\5.2.0\mingw48_32\plugins\sqldrivers
and
C:\Qt\Qt5.2.0\5.2.0\msvc2012_64\plugins\sqldrivers

[A Former User]

and For Linux about ldd :

root@Gigabyte-Z68P-DS3:~# ldd /bin/date
linux-vdso.so.1 => (0x00007fff31d72000)
librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f0ea438c000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f0ea3fc4000)
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f0ea3da6000)
/lib64/ld-linux-x86-64.so.2 (0x00007f0ea45b5000)

and about MySQL plugin folder and files:

in here :

/opt/Qt5.2.0/5.2.0/gcc_64/plugins/sqldrivers .... I have libqsqlmysql.so

[SGaist]

I know where your dlls are. If using 64bit, the question is: is "C:\Program Files\MySQL\MySQL Server 5.6\lib" contained in the PATH environment variable in the Run section on the Project panel in Qt Creator ?

I didn't ask you to run ldd on /bin/date but on your Qt 5.2.0 libqsqlmysql.so

[A Former User]

[quote author="SGaist" date="1388785738"]I know where your dlls are. If using 64bit, the question is: is "C:\Program Files\MySQL\MySQL Server 5.6\lib" contained in the PATH environment variable in the Run section on the Project panel in Qt Creator ?
[/quote]

OMG! NO...
Sorry ! I forget PATH environment variable !!! now my problem is sloved on Windows by add PATH environment variable for Mysql :)

but for linux ?! can you give me more information ?

[SGaist]

You already have all the information: call "ldd /opt/Qt5.2.0/5.2.0/gcc_64/plugins/sqldrivers/libqsqlmysql.so"

to see what libraries it links to

[A Former User]

[quote author="SGaist" date="1388788157"]You already have all the information: call "ldd /opt/Qt5.2.0/5.2.0/gcc_64/plugins/sqldrivers/libqsqlmysql.so"

to see what libraries it links to[/quote]

This is :

root@Gigabyte-Z68P-DS3:~# ldd /opt/Qt5.2.0/5.2.0/gcc_64/plugins/sqldrivers/libqsqlmysql.so
linux-vdso.so.1 => (0x00007fff2c89b000)
libmysqlclient_r.so.16 => not found
libQt5Sql.so.5 => /opt/Qt5.2.0/5.2.0/gcc_64/plugins/sqldrivers/../../lib/libQt5Sql.so.5 (0x00007f23cac7a000)
libQt5Core.so.5 => /opt/Qt5.2.0/5.2.0/gcc_64/plugins/sqldrivers/../../lib/libQt5Core.so.5 (0x00007f23ca5ac000)
libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f23ca2a8000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f23c9ee0000)
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f23c9cc2000)
libicui18n.so.51 => /opt/Qt5.2.0/5.2.0/gcc_64/plugins/sqldrivers/../../lib/libicui18n.so.51 (0x00007f23c98a9000)
libicuuc.so.51 => /opt/Qt5.2.0/5.2.0/gcc_64/plugins/sqldrivers/../../lib/libicuuc.so.51 (0x00007f23c9523000)
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f23c931e000)
libgthread-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgthread-2.0.so.0 (0x00007f23c911c000)
librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f23c8f14000)
libglib-2.0.so.0 => /lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007f23c8c12000)
libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f23c890e000)
libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f23c86f8000)
/lib64/ld-linux-x86-64.so.2 (0x00007f23cb0ec000)
libicudata.so.51 => /opt/Qt5.2.0/5.2.0/gcc_64/plugins/sqldrivers/../../lib/libicudata.so.51 (0x00007f23c6fae000)
libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007f23c6d6f000)
root@Gigabyte-Z68P-DS3:~#

[SGaist]

You have it on the second line:

@libmysqlclient_r.so.16 => not found@

Check what version number of libmysqlclient_r you have installed

[A Former User]

[quote author="SGaist" date="1388870467"]You have it on the second line:

@libmysqlclient_r.so.16 => not found@

Check what version number of libmysqlclient_r you have installed[/quote]

root@Gigabyte-Z68P-DS3:~# dpkg --get-selections | grep mysql
libmysql++-dev install
libmysql++3 install
libmysqlclient-dev install
libmysqlclient18:amd64 install
libmysqlclient18:i386 install
libmysqlcppconn-dev install
libmysqlcppconn7 install
libqt4-sql-mysql:amd64 install
libqt4-sql-mysql:i386 install
libqt5sql5-mysql:amd64 install
mysql-client-core-5.5 install
mysql-common install
root@Gigabyte-Z68P-DS3:~#

[SGaist]

You have the version 18 and not the 16.

So two solutions here:

1. find the version 16
2. build the Qt MySQL plugin yourself with this version of the client library (best)

[A Former User]

[quote author="SGaist" date="1388875572"]You have the version 18 and not the 16.

So two solutions here:

find the version 16

build the Qt MySQL plugin yourself with this version of the client library (best)[/quote]

Sorry , but can you help me for find or build qt mysql plugin ?
I run this command : root@Gigabyte-Z68P-DS3:/opt/Qt5.2.0/5.2.0/Src/qtbase/src/plugins/sqldrivers/mysql# qmake "INCLUDEPATH+=/usr/include/mysql" "LIBS+=-L/usr/lib/mysql -lmysqlclient_r" mysql.pro

I think my command is not true ! in QT 5.2 any folders and roots is different...

[SGaist]

did you call make after that ?

[A Former User]

I run first this command : root@Gigabyte-Z68P-DS3:~# cd /opt/Qt5.2.0/5.2.0/Src/qtbase/src/plugins/sqldrivers/mysql

after :

root@Gigabyte-Z68P-DS3:/opt/Qt5.2.0/5.2.0/Src/qtbase/src/plugins/sqldrivers/mysql# qmake "INCLUDEPATH+=/usr/include/mysql" "LIBS+=-L/usr/lib/mysql -lmysqlclient_r" mysql.pro
qmake: could not find a Qt installation of ''
root@Gigabyte-Z68P-DS3:/opt/Qt5.2.0/5.2.0/Src/qtbase/src/plugins/sqldrivers/mysql#