[SOLVED] QSqlDatabase: QMYSQL driver not loaded

[Antweb]

I read a lot of forums but am still getting into trouble making this work. I'm working on Ubuntu 15.04.
I used ldd on my libqsqlmysql.so, so it showed libmysqlclient_r.so.16 not found.
I had libmysqlclient_r.so and libmysqlclient_r.so.18 in my library. I linked these both to my .16 file and tried running separately but it still did not run.
Then i saw the method of building the QMYSQL plugin into my sqldrivers folder.
So i did this:
qmake "INCLUDEPATH+=/usr/include/mysql" "LIBS+=-L/usr/lib/mysql -lmysqlclient_r" mysql.pro

Ater this when i run make,
it gives me the following error:
g++ -c -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -D_FORTIFY_SOURCE=2 -I/usr/include/mysql -O2 -fvisibility=hidden -fvisibility-inlines-hidden -std=c++0x -fno-exceptions -Wall -W -D_REENTRANT -fPIC -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/mysql -isystem /usr/include/x86_64-linux-gnu/qt5/QtCore/5.4.1 -isystem /usr/include/x86_64-linux-gnu/qt5/QtCore/5.4.1/QtCore -isystem /usr/include/x86_64-linux-gnu/qt5/QtSql/5.4.1 -isystem /usr/include/x86_64-linux-gnu/qt5/QtSql/5.4.1/QtSql -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 -I../../../../mkspecs/linux-g++-64 -o .obj/main.o main.cpp
In file included from main.cpp:67:0:
main.moc:12:2: error: #error "This file was generated using the moc from 4.8.6. It"
#error "This file was generated using the moc from 4.8.6. It"
^
main.moc:13:2: error: #error "cannot be used with the include files from this version of Qt."
#error "cannot be used with the include files from this version of Qt."
^
main.moc:14:2: error: #error "(The moc has changed too much.)"
#error "(The moc has changed too much.)"
^
main.moc:46:7: error: ‘QMetaObjectExtraData’ does not name a type
const QMetaObjectExtraData QMYSQLDriverPlugin::staticMetaObjectExtraData = {
^
main.moc:52:41: error: ‘staticMetaObjectExtraData’ was not declared in this scope
qt_meta_data_QMYSQLDriverPlugin, &staticMetaObjectExtraData }
^
main.moc: In member function ‘virtual const QMetaObject* QMYSQLDriverPlugin::metaObject() const’:
main.moc:61:71: error: conditional expression between distinct pointer types ‘QDynamicMetaObjectData*’ and ‘const QMetaObject*’ lacks a cast
return QObject::d_ptr->metaObject ? QObject::d_ptr->metaObject : &staticMetaObject;
^
main.moc:62:1: warning: control reaches end of non-void function [-Wreturn-type]
}
^
Makefile:393: recipe for target '.obj/main.o' failed
make: *** [.obj/main.o] Error 1

This is my program:
QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");
db.setHostName("localhost");
db.setDatabaseName("student_info");
db.setUserName("root");
db.setPassword("terron@2003");
bool ok = db.open();
qDebug() << ok;
db.close();

I don't know what to do any further. Please Help.

[SGaist]

Hi and welcome to devnet,

It seems you are trying to build a moc file that was generated when using Qt 4.8.6. Remove any moc file from your sources and restart the build.

[Antweb]

Worked Perfectly. Thanks a lot Sir.

[SGaist]

You're welcome !

Since you have it working now, please update the thread title prepending [solved] so other forum users may know a solution has been found :)

Also, consider up-voting the answer(s) that helped you, it will allow other members to find them more easily.