Error while compiling Qt mySQL driver

denko · 1 Aug 2017, 16:29

Hello guys,

Im getting this error while trying to connect to a database in my Qt project:
QSqlDatabase: QMYSQL driver not loaded
QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QPSQL QPSQL7

libqsqlmysql.so it is located in my sqldrivers, mysql client and server are installed on my machine Im using Ubuntu 17 and Qt 5.9.

When I tried ldd libqsqlmysql.so I get this: libmysqlclient.so.18 => not found, so I tried to compile a new one from qtbase(source code) but when I run:

qmake "INCLUDEPATH+=MYSQL INCLUDE LOCATION" "LIBS+=-L MYSQL LIB LOCATION" mysql.pro a Makefile is created but I get this error too:

Cannot read /home/[My Username]/Desktop/qtbase-dev/src/plugins/sqldrivers/qtsqldrivers-config.pri: No such file or directory

When I enter make, I get this error:
/usr/bin/ld: cannot find /usr/lib/mysql: File format not recognized
collect2: error: ld returned 1 exit status
Makefile:73: recipe for target '../plugins/sqldrivers/libqsqlmysql.so' failed
make: *** [../plugins/sqldrivers/libqsqlmysql.so] Error 1

So this seems pretty annoying, any help is welcome :)

SGaist · wrote on 1 Jul 2017, 22:28

Hi and welcome to devnet,

What version of MySQL did you install ? Are you building or cross-compiling ?

denko · wrote on 1 Jul 2017, 22:33

MySQL version: 5.7.18
What Im trying to do is to build a newer version of libqsqlmysql because with the older one I get the above mentioned error: QSqlDatabase: QMYSQL driver not loaded, from reading a lot of threads I saw that you need to build it yourself to fit your mySql version.

denko · wrote on 2 Jul 2017, 13:46

I solved the problem with installing libmysqlclient18 package.

tntneo · wrote on 3 Jul 2017, 15:32

Same issue here.
How did you install libmysqlclient18 ?

Avtansh Sharma · wrote on 12 Jul 2017, 10:42

@tntneo said in Error while compiling Qt mySQL driver:

libmysqlclient18

https://packages.ubuntu.com/trusty/libmysqlclient18

mbnoimi · 7 Dec 2017, 18:46

Hi guys,

I've same issue although I already installed libmysqlclient20 and libmysqlclient-dev and run:
sudo ln -s /usr/lib/x86_64-linux-gnu/libmysqlclient.so /usr/lib/x86_64-linux-gnu/libmysqlclient_r.so as mentioned here:

May I get some help here.

Thanks in advance.

I'm using:

Qt 5.9.1
MySQL 5.7.18
Linux Mint 18.2 x64 xfce (Ubuntu 16.04)

log

$ /home/mogla/.Qt/5.9.1/gcc_64/bin/qmake
Cannot read /home/mogla/.Qt/5.9.1/Src/qtbase/src/plugins/sqldrivers/qtsqldrivers-config.pri: No such file or directory
$ ls /home/mogla/.Qt/5.9.1/Src/qtbase/src/plugins/sqldrivers/
configure.json	configure.pri  db2  ibase  lib	mkspecs  mysql	oci  odbc  plugins  psql  qsqldriverbase.pri  README  sqldrivers.pro  sqlite  sqlite2  tds
$

IMPORTANT:
This issue occurs with Qt 5.9.1 while doesn't with Qt 5.8!

SGaist · 7 Dec 2017, 20:13

Hi,

Looks like it's a generated file however I don't know yet exactly how it is generated.

In between, you can try to use that one:

QT.sqldrivers.enabled_features =
QT.sqldrivers.disabled_features =
QT.sqldrivers.QT_CONFIG =
QT.sqldrivers.exports =
QT.sqldrivers_private.enabled_features = sql-sqlite sql-mysql
QT.sqldrivers_private.disabled_features = sql-db2 sql-ibase sql-oci sql-odbc sql-psql sql-sqlite2 sql-tds system-sqlite
QT.sqldrivers_private.libraries =

It's based on one of my builds.

mbnoimi · S SGaist 12 Jul 2017, 20:09

@SGaist said in Error while compiling Qt mySQL driver:

Hi,

Looks like it's a generated file however I don't know yet exactly how it is generated.

In between, you can try to use that one:
QT.sqldrivers.enabled_features =
QT.sqldrivers.disabled_features =
QT.sqldrivers.QT_CONFIG =
QT.sqldrivers.exports =
QT.sqldrivers_private.enabled_features = sql-sqlite sql-mysql
QT.sqldrivers_private.disabled_features = sql-db2 sql-ibase sql-oci sql-odbc sql-psql sql-sqlite2 sql-tds system-sqlite
QT.sqldrivers_private.libraries =
It's based on one of my builds.

Where can I use these configs?!

SGaist · wrote on 13 Jul 2017, 08:05

That's the content of the generated qtsqldrivers-config.pri I have.

mbnoimi · S SGaist 12 Jul 2017, 20:09

@SGaist said in Error while compiling Qt mySQL driver:

Hi,

Looks like it's a generated file however I don't know yet exactly how it is generated.

In between, you can try to use that one:
QT.sqldrivers.enabled_features =
QT.sqldrivers.disabled_features =
QT.sqldrivers.QT_CONFIG =
QT.sqldrivers.exports =
QT.sqldrivers_private.enabled_features = sql-sqlite sql-mysql
QT.sqldrivers_private.disabled_features = sql-db2 sql-ibase sql-oci sql-odbc sql-psql sql-sqlite2 sql-tds system-sqlite
QT.sqldrivers_private.libraries =
It's based on one of my builds.

I created a new file depending on yours. qmake done fine while make gave me this error:

$ make
g++ -c -pipe -O2 -std=c++1z -fvisibility=hidden -fvisibility-inlines-hidden -fno-exceptions -Wall -W -Wvla -Wdate-time -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. -I/home/mbnoimi/.Qt/5.9.1/gcc_64/include/QtSql/5.9.1 -I/home/mbnoimi/.Qt/5.9.1/gcc_64/include/QtSql/5.9.1/QtSql -I/home/mbnoimi/.Qt/5.9.1/gcc_64/include/QtCore/5.9.1 -I/home/mbnoimi/.Qt/5.9.1/gcc_64/include/QtCore/5.9.1/QtCore -I/home/mbnoimi/.Qt/5.9.1/gcc_64/include -I/home/mbnoimi/.Qt/5.9.1/gcc_64/include/QtSql -I/home/mbnoimi/.Qt/5.9.1/gcc_64/include/QtCore -I.moc -I/home/mbnoimi/.Qt/5.9.1/gcc_64/mkspecs/linux-g++ -o .obj/qsql_mysql.o qsql_mysql.cpp
In file included from qsql_mysql.cpp:40:0:
qsql_mysql_p.h:60:19: fatal error: mysql.h: No such file or directory
compilation terminated.
Makefile:773: recipe for target '.obj/qsql_mysql.o' failed
make: *** [.obj/qsql_mysql.o] Error 1
$

mbnoimi · wrote on 13 Jul 2017, 08:15

I wonder, does this issue is a new bug in Qt 5.9.1 because as I said before "Qt 5.8 works fine"

SGaist · wrote on 13 Jul 2017, 11:25

The build system has changed so it looks rather like a documentation bug.

mbnoimi · wrote on 20 Jul 2017, 18:58

Qt plugins really pain in the ass... I'm very frustrated!!!

It seems I've to rollback to Microsoft products after years of using Qt. Because of this stupid policy of Qt I always spend hours and hours on deployment or building a stupid plugin which suppose to be available in the binary distro!!!

Why the developer needs to rebuild anything from source code if he/she chose to use binary distro of Qt!!!

Any way, I filed a bug report about this stupid bug in this link:
https://bugreports.qt.io/browse/QTBUG-62078

For whom concern:
https://forum.qt.io/topic/81272/licenses-craziness

Eduardo12l · 22 Jul 2017, 20:45

Have you qMake it?

mbnoimi · wrote on 22 Jul 2017, 20:45

@Eduardo12l Yes

Mohammad Kanan · 1 Aug 2017, 20:31

@All, You do not really need to rebuild the plugin! I guess you may get same error even after recompile.
Why: from the output, Qt creator, does not say there is any problem with QMYSQL, everything seems to be OK, except linking to the correct driver/lib, best to do is to try these steps first of all:

download the 32-bit version of mysql connector/c from:
libmysql 32 bit version
on Linux/Mac we get (mysql-connector-c-6.0.2-osx10.5-x86-32bit.tar)
untar, and install the package (with defaults), you should get the driver installed at :
/usr/local/mysql-connector-c-6.0.2-osx10.5-x86-32bit/lib/libmysql.dylib
Then copy it to your build folder ( <your Base Qt location>/5.9.1/clang_64/bin) ... for test -> rebuild your solution and should not show that error again, plus, database connectivity should work.
if it works then, instead of keeping the copied library at the qt bin directory, best is to remove it and add library to your project:
delete the file you copied to clang_64/bin .
in your project add library pointing to the downloaded 32 bit libmysql.dll (right click -> add library -> external)
(adding as library is suitable later for deployment).

mbnoimi · 3 Aug 2017, 19:32

Thanks a lot @Mohammad-Kanan your solution worked but I used mysql-connector-c-6.1.11-linux-glibc2.12-x86_64 instead of 32 bit version

I struggled with this issue for 15 days then I surrendered

Mohammad Kanan · wrote on 3 Aug 2017, 19:32

@mbnoimi Good news! 32 or 64 bit depends on your system. I use Qt 32 bit on Win10, 64 bit, I don't know 64 bit one exists :) in my case the 64 bit lib didn't help.

chrabaszcz.patryk · 8 Mar 2018, 13:51

Hi I had the same problem with qtsqldrivers-config.pri

I leave it here, maybe it will be helpful

Go to :
/Qt_new/5.9.1/Src/qtbase/src/plugins/sqldrivers
Run qmake:
../../../../../gcc_64/bin/qmake sqldrivers.pro
After that I got:

Configure summary:

Qt Sql:
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

Then go to:
/Qt_new/5.9.1/Src/qtbase/src/plugins/sqldrivers/mysql
Run qmake again:
../../../../../../gcc_64/bin/qmake mysql.pro
Run make:
make
You will see as a part of an output message that it was compiled and moved into:
"mv -f libqsqlmysql.so ../plugins/sqldrivers/"