QSqlDatabase: QMYSQL driver not loaded QSqlDatabase: available drivers: QSQLITE QMYSQL

jollyto

Platform: OS X
Qt 5.5.1
Code:

QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");
db.setPort(3306);
db.setHostName("aName");
db.setDatabaseName("foo");
db.setUserName("aaa");
db.setPassword("bbbb");

if (!db.open()) {
    QMessageBox::warning(0,
                         QObject::tr("Database Error"),
                         db.lastError().text());
    return false;
}

Output:

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

Part of .pro file
QT += core gui
QT += sql

QTPLUGIN += qsqlmysql

...

Any ideas.

Thanks

SGaist

Hi and welcome to devnet,

Please search the forum a bit, that question has been asked many times already.

Do you have the MySQL client library installed ? If so, what version are they ?

You can check the currently link library by running "otool -L libqsqlmysql.dylib"

lotusgenerat

@SGaist
Hello sir i have the same exact problem, i'm running osx 10.11, QT 5.5 , and MySQL server.
I tried to read most of the post in the forum but couldn't find the solution.

here's the otool -L libqsqlmysql.dylib
applications/5.5/clang_64/plugins/sqldrivers/libqsqlmysql.dylib:
libqsqlmysql.dylib (compatibility version 0.0.0, current version 0.0.0)
/opt/local/lib/mysql55/mysql/libmysqlclient.18.dylib (compatibility version 18.0.0, current version 18.0.0)
/usr/lib/libz.1.dylib (compatibility version 1.0.0, current version 1.2.5)
@rpath/QtSql.framework/Versions/5/QtSql (compatibility version 5.5.0, current version 5.5.0)
@rpath/QtCore.framework/Versions/5/QtCore (compatibility version 5.5.0, current version 5.5.0)
/System/Library/Frameworks/DiskArbitration.framework/Versions/A/DiskArbitration (compatibility version 1.0.0, current version 1.0.0)
/System/Library/Frameworks/IOKit.framework/Versions/A/IOKit (compatibility version 1.0.0, current version 275.0.0)
/usr/lib/libc++.1.dylib (compatibility version 1.0.0, current version 120.0.0)
/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1213.0.0)

i read that some of the users create a folder in
/opt/local/lib/mysql55/mysql/libmysqlclient20.dylib
that doesn't solve the problem.

any idea?
thanks

SGaist

Hi and welcome to devnet,

Do you have the MySQL client libraries installed on your system ?

lotusgenerat

@SGaist
yes i guess
i installed mysql community server and sql workbench.
did u mean the library in :
/usr/local/mysql/lib

SGaist

Then use install_name_tool to change the path from /opt/local/lib/mysql55/mysql/libmysqlclient.18.dylib to the path where your libmysqlclient can be found in /usr/local/mysql/

lotusgenerat

@SGaist
Actually there is no mysql on /opt/ folder so i create it as the path you stated
/opt/local/lib/mysql55/mysql/libmysqlclient.20.dylib
then i coppied the libmysqlclient.20.dylib from /usr/local/mysql/lib/

did libmysqlclient20 same as the 18? or i need to change it to 18?

after create it, then i did
install_name_tool -change /opt/local/lib/mysql55/mysql/lib/libqsqlmysql.20.dylib /usr/local/mysql/lib/libmysqlclient.dylib

it returned
Usage: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/install_name_tool [-change old new] ... [-rpath old new] ... [-add_rpath new] ... [-delete_rpath old] ... [-id name] input

maybe i miss something?

SGaist

Don't copy files around.

Your install_name_tool line is wrong. It should rather be something like

install_name_tool -change /opt/local/lib/mysql55/mysql/libmysqlclient.18.dylib /usr/local/mysql/lib/libmysqlclient.20.dylib path/to/libqsqlmysql.dylib

I don't know whether the changes between 18 and 20 requires a rebuild of the plugin.

lotusgenerat

@SGaist
Wow that solve the problem.
Thankyou very much Sir !

SGaist

You're welcome !

Since you have it working now, please mark the thread as solved using the "Topic Tool" button so other forum users may know a solution has been found :)

Also, while browsing the forum, consider up-voting answers that helped you, it will make them easier to find for other users :)

JeremyTam

@SGaist My platform is OS X. I have tried your method.
What terminal outputs is

libqsqlmysql.dylib (compatibility version 0.0.0, current version 0.0.0)
/usr/local/Cellar/mysql/5.7.16/lib/libmysqlclient.20.dylib (compatibility version 18.0.0, current version 18.0.0)
/usr/lib/libz.1.dylib (compatibility version 1.0.0, current version 1.2.5)
@rpath/QtSql.framework/Versions/5/QtSql (compatibility version 5.5.0, current version 5.5.1)
@rpath/QtCore.framework/Versions/5/QtCore (compatibility version 5.5.0, current version 5.5.1)
/System/Library/Frameworks/DiskArbitration.framework/Versions/A/DiskArbitration (compatibility version 1.0.0, current version 1.0.0)
/System/Library/Frameworks/IOKit.framework/Versions/A/IOKit (compatibility version 1.0.0, current version 275.0.0)
/usr/lib/libc++.1.dylib (compatibility version 1.0.0, current version 120.0.0)
/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version

Sttill not working1213.0.0)

SGaist

Hi,

Doesn't work doesn't help much.

What exactly doesn't work ?
What error message do you get ?