I Can't able to connect QMYSQL Driver in QT Creator 4.9.2 and QT 5.12.4

[Surendar Dharani]

Hi,

Please help me connect QT with Mysql.

When i tries it showing following error.

OS : Ubuntu 18.04 64 bit

Error :

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

QT : Using Open Source Licence.

I am new to QT and CPP so please guide me step by step.

Thanks in advance.

[SGaist]

Hi and welcome to devnet,

Please take the time to search this forum for this kind of question, it has been asked many times already.

[Surendar Dharani]

Can you please share some links for that. Because i tried there is all solutions only for windows system but i need ubuntu OS. Thanks in advance.

[SGaist]

Strange, the seconde hit of google points here.

[Surendar Dharani]

Hi I got this when i runs ldd,

linux-vdso.so.1 (0x00007ffe64dc3000)
libQt5Sql.so.5 => /opt/Qt/5.9/gcc_64/plugins/sqldrivers/./../../lib/libQt5Sql.so.5 (0x00007f0594b18000)
libQt5Core.so.5 => /opt/Qt/5.9/gcc_64/plugins/sqldrivers/./../../lib/libQt5Core.so.5 (0x00007f05943e0000)
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f05941c1000)
libmysqlclient.so.18 => not found
libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f0593e38000)
libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f0593a9a000)
libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f0593882000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f0593491000)
libicui18n.so.56 => /opt/Qt/5.9/gcc_64/plugins/sqldrivers/./../../lib/libicui18n.so.56 (0x00007f0592ff8000)
libicuuc.so.56 => /opt/Qt/5.9/gcc_64/plugins/sqldrivers/./../../lib/libicuuc.so.56 (0x00007f0592c40000)
libicudata.so.56 => /opt/Qt/5.9/gcc_64/plugins/sqldrivers/./../../lib/libicudata.so.56 (0x00007f059125d000)
librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f0591055000)
libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f0590e38000)
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f0590c34000)
libgthread-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgthread-2.0.so.0 (0x00007f0590a32000)
libglib-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007f059071b000)
/lib64/ld-linux-x86-64.so.2 (0x00007f0594f72000)
libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007f05904a9000)

[SGaist]

Well, following the thread I pointed you to, what version of MySQL do you have on your city ?

[Surendar Dharani]

@sgaist in my system mysql version is,

mysql Ver 14.14 Distrib 5.7.27, for Linux (x86_64) using Editline wrapper

[Surendar Dharani]

Hi,

Following is my response when i tried qmake please help me.

root@surendar:/opt/Qt/5.9/Src/qtbase/src/plugins/sqldrivers/mysql# qmake "INCLUDEPATH+=/usr/include/mysql" "LIBS+=-L/usr/lib/mysql -lmysqlclient_r" mysql.pro
Project ERROR: Library 'mysql' is not defined.

[SGaist]

So your version of MySQL is way older than the one used to build the Qt plugin.

Two options:

• like already suggested in the thread linked build the plugin against the version of MySQL you have installed.
• use the Qt version provided by your distribution if you don't use any API available in a newer version.

You should also take into account that you are using a 5 years old distribution, you should consider updating.

[Surendar Dharani]

@sgaist said in I Can't able to connect QMYSQL Driver in QT Creator 4.9.2 and QT 5.12.4:

older

I am updating QT 5.9 to 5.13.0

And i got this error when i tried qtbase configure.

Error:

root@surendar:/opt/Qt/5.9/Src/qtbase/src/plugins/sqldrivers/mysql# qmake "INCLUDEPATH+=/usr/include/mysql" "LIBS+=-L/usr/lib/mysql -lmysqlclient_r" mysql.pro
Project ERROR: Library 'mysql' is not defined.

Once QT update finished will let you know. Thanks.

[SGaist]

Don't build as root.

As for building the plugin, follow the related documentation.

[Surendar Dharani]

@surendar-dharani said in I Can't able to connect QMYSQL Driver in QT Creator 4.9.2 and QT 5.12.4:

qmake "INCLUDEPATH+=/usr/include/mysql" "LIBS+=-L/usr/lib/mysql -lmysqlclient_r" mysql.pro

I tried to qmake but it showing follwoing error again, Please help.

acer@surendar:/opt/Qt/5.13.0/Src/qtbase/src/plugins/sqldrivers/mysql$ qmake "INCLUDEPATH+=/usr/include/mysql" "LIBS+=-L/usr/lib/mysql -lmysqlclient_r" mysql.pro
Info: creating stash file /opt/Qt/5.13.0/Src/qtbase/src/plugins/sqldrivers/.qmake.stash
Cannot read /opt/Qt/5.13.0/Src/qtbase/src/plugins/sqldrivers/qtsqldrivers-config.pri: No such file or directory
Project ERROR: Library 'mysql' is not defined.

[SGaist]

Please follow the documentation.

[Surendar Dharani]

Sorry for asking again and again,

I got this error now after i followed the document,

acer@surendar:/opt/Qt/5.13.0/Src/qtbase/src/plugins/sqldrivers/mysql$ make install
make: *** No rule to make target 'install'. Stop.

and when i tried ./configure -sql-mysql error is like

ERROR: Feature 'sql-mysql' was enabled, but the pre-condition 'libs.mysql' failed.

[Surendar Dharani]

Please anyone help on this. Thanks a lot in advance

[SGaist]

Please show some patience before bumping your own thread. People answering here do it voluntarily and might not live in the same time zone as you.

Did you install the MySQL development package from your distribution ?

[RonaldViscarraL]

Hi, in most of linux distros, there's not mysql, but mariadb, if this is the case, then you need to make a soft link to mariadb lib and call it like the mysql required

[Surendar Dharani]

@ronaldviscarral Hi,

Thank you very much. Please tell me how to do it by step by step. Because i'm new in this. Thanks in advance.

[RonaldViscarraL]

@surendar-dharani sure, first, install mariadb in your linux distro, then as super user in a terminal (for a x64 base system):

ln -s /usr/lib64/libmariadb.so.3 /usr/lib64/libmysqlclient.so.18

you should adapt it to your distro paths and mariadb version

[Surendar Dharani]

@ronaldviscarral said in I Can't able to connect QMYSQL Driver in QT Creator 4.9.2 and QT 5.12.4:

ln -s /usr/lib64/libmariadb.so.3 /usr/lib64/libmysqlclient.so.18

Hi,

I have uninstalled by using following commands and installed maria DB.

sudo apt-get remove --purge mysql-server mysql-client mysql-common

installed mariadb by follwing command,
sudo apt-get install mariadb-server

And tried to compile same driver not laoded in mysql

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

Now what to i do?

[SGaist]

Start your application with the QT_DEBUG_PLUGINS environment variable set to 1.

You'll see what is happening with your plugin.

[RonaldViscarraL]

@surendar-dharani Your OS seems to have mysql, so, better install them.

If you didn't compile the mysql driver, you could guide you with:
https://fecub.wordpress.com/2014/08/12/compilecreate-mysql-driver-for-qt5-on-windows/

When you build an app that's use mysql driver, and the plugin is compiled, and there's no mysql library availible in your system, you have the error:

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

notice that QMYSQL is availible but not loaded, means that the plugin is compiled but the library was not found it.

so, having been installed mysql-server and mysql-client from your package manager, find the library libmysqlclient.so.18, in a terminal you could use as super user:

find / -name libmysqlclient.so.18 

paste here the results to check it out

[Surendar Dharani]

@ronaldviscarral @SGaist Hi have installed in my other system from the scratch itself, Now i got this.

When i ran this sh configure -sql-mysql

Output:

Qt Sql Drivers:
DB2 (IBM) .............................. no
InterBase .............................. no
MySql .................................. yes
OCI (Oracle) ........................... no
ODBC ................................... no
PostgreSQL ............................. no
SQLite2 ................................ no
SQLite ................................. yes
Using system provided SQLite ......... no
TDS (Sybase) ........................... no

And i tried to run QT 5.13.1

And I got this ,

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

And I checked in /opt/Qt/5.13.1/gcc_64/plugins/sqldrivers/

But libqsqlmysql.so file is not found in this location.

i think little thing is missing here. Please guide me. Thanks in advance.

[Quang Phu]

Hi @Surendar-Dharani ,
you have to install QMYSQL plugin first.
I met this issue before and have 2 topics that you can refer
https://forum.qt.io/topic/106421/qt-mac-version-doesn-t-have-file-libqsqlmysql-dylib
https://forum.qt.io/topic/106565/mysql-qt-create-plugin-mysql-for-qt-on-mac

[Surendar Dharani]

@quang-phu @SGaist @RonaldViscarraL

when i run this /opt/Qt/5.13.1/Src/qtbase/src/plugins/sqldrivers# make sub-mysql

I got this :
cd mysql/ && ( test -e Makefile || /usr/lib/qt5/bin/qmake -o Makefile /opt/Qt/5.13.1/Src/qtbase/src/plugins/sqldrivers/mysql/mysql.pro MYSQL_PREFIX=/usr/local ) && make -f Makefile
make[1]: Entering directory '/opt/Qt/5.13.1/Src/qtbase/src/plugins/sqldrivers/mysql'
g++ -c -g -O2 -fdebug-prefix-map=/build/qtbase-opensource-src-5DihdB/qtbase-opensource-src-5.9.5+dfsg=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -O2 -std=c++1z -fvisibility=hidden -fvisibility-inlines-hidden -fno-exceptions -Wall -W -Wvla -Wdate-time -Wshift-overflow=2 -Wduplicated-cond -Wno-stringop-overflow -D_REENTRANT -fPIC -DQT_NO_NARROWING_CONVERSIONS_IN_CONNECT -DQT_NO_CAST_TO_ASCII -DQT_NO_CAST_FROM_ASCII -DQT_NO_EXCEPTIONS -D_LARGEFILE64_SOURCE -D_LARGEFILE_SOURCE -DQT_NO_DEBUG -DQT_PLUGIN -DQT_SQL_LIB -DQT_CORE_LIB -I. -isystem /usr/include/x86_64-linux-gnu/qt5/QtSql/5.9.5 -isystem /usr/include/x86_64-linux-gnu/qt5/QtSql/5.9.5/QtSql -isystem /usr/include/x86_64-linux-gnu/qt5/QtCore/5.9.5 -isystem /usr/include/x86_64-linux-gnu/qt5/QtCore/5.9.5/QtCore -isystem /usr/include/x86_64-linux-gnu/qt5 -isystem /usr/include/x86_64-linux-gnu/qt5/QtSql -isystem /usr/include/x86_64-linux-gnu/qt5/QtCore -I.moc -isystem /usr/include/mysql -I/usr/lib/x86_64-linux-gnu/qt5/mkspecs/linux-g++ -o .obj/qsql_mysql.o qsql_mysql.cpp
In file included from /usr/include/x86_64-linux-gnu/qt5/QtSql/qtsqlglobal.h:43:0,
from /usr/include/x86_64-linux-gnu/qt5/QtSql/qsqldriver.h:43,
from qsql_mysql_p.h:54,
from qsql_mysql.cpp:40:
qsql_mysql.cpp:1469:5: error: division by zero in #if
#if QT_CONFIG(thread)
^
qsql_mysql.cpp:1483:5: error: division by zero in #if
#if QT_CONFIG(thread)
^
qsql_mysql.cpp: In function ‘QSqlField qToField(MYSQL_FIELD, QTextCodec)’:
qsql_mysql.cpp:344:44: error: no matching function for call to ‘QSqlField::QSqlField(QString, QVariant::Type, QString)’
toUnicode(tc, field->table));
^
In file included from qsql_mysql.cpp:46:0:
/usr/include/x86_64-linux-gnu/qt5/QtSql/qsqlfield.h:60:5: note: candidate: QSqlField::QSqlField(const QSqlField&)
QSqlField(const QSqlField& other);
^~~~~~~~~
/usr/include/x86_64-linux-gnu/qt5/QtSql/qsqlfield.h:60:5: note: candidate expects 1 argument, 3 provided
/usr/include/x86_64-linux-gnu/qt5/QtSql/qsqlfield.h:57:14: note: candidate: QSqlField::QSqlField(const QString&, QVariant::Type)
explicit QSqlField(const QString& fieldName = QString(),
^~~~~~~~~
/usr/include/x86_64-linux-gnu/qt5/QtSql/qsqlfield.h:57:14: note: candidate expects 2 arguments, 3 provided
Makefile:376: recipe for target '.obj/qsql_mysql.o' failed
make[1]: [.obj/qsql_mysql.o] Error 1
make[1]: Leaving directory '/opt/Qt/5.13.1/Src/qtbase/src/plugins/sqldrivers/mysql'
Makefile:42: recipe for target 'sub-mysql' failed
make: [sub-mysql] Error 2**

and when i ran sh configure in qtbase folder i got this,

g++: error: /opt/Qt/5.13.1/Src/qtbase/lib/libqtpcre2.a: No such file or directory
Makefile:1214: recipe for target '../../lib/libQt5Core.so.5.13.1' failed
make[2]: *** [../../lib/libQt5Core.so.5.13.1] Error 1
make[2]: Leaving directory '/opt/Qt/5.13.1/Src/qtbase/src/corelib'
Makefile:213: recipe for target 'sub-corelib-install_subtargets' failed
make[1]: *** [sub-corelib-install_subtargets] Error 2
make[1]: Leaving directory '/opt/Qt/5.13.1/Src/qtbase/src'
Makefile:62: recipe for target 'sub-src-install_subtargets' failed
make: *** [sub-src-install_subtargets] Error 2

[SGaist]

From the looks of it, you are mixing several versions of Qt.
There's references to both Qt 5.13 and Qt 5.9.5 which is not a good sign.

[Surendar Dharani]

@sgaist hi,

How to do it for version 5.13.1

Because i got confused. Now what I have to do?

Uninstall 5.9 version and try qmakr for 5.13.1 version?

[Surendar Dharani]

Hi,

I got output.

In terminal,

I just ran sh configure -sql-mysql
after that ran make
after that ran make install

Thanks for your valuable support and valuable time.