QSqlDatabase crashes when can't connect

Thread 2 (Thread 4616.0x4a0):
#0  0x778e015d in ntdll!ZwWaitForMultipleObjects () from C:\Windows\SysWOW64\ntdll.dll
No symbol table info available.
#1  0x778e015d in ntdll!ZwWaitForMultipleObjects () from C:\Windows\SysWOW64\ntdll.dll
No symbol table info available.
#2  0x77912f91 in ntdll!RtlMoveMemory () from C:\Windows\SysWOW64\ntdll.dll
No symbol table info available.
#3  0x00000001 in ?? ()
No symbol table info available.
#4  0x00000001 in ?? ()
No symbol table info available.
#5  0x00000000 in ?? ()
No symbol table info available.

Thread 1 (Thread 4616.0x1378):
#0  0x540b0563 in ?? () from G:\SOFT\MySQL\mysql-connector-c-6.1.0-win32\lib\libmysql.dll
No symbol table info available.
#1  0x540b0799 in ?? () from G:\SOFT\MySQL\mysql-connector-c-6.1.0-win32\lib\libmysql.dll
No symbol table info available.
#2  0x540b9aed in mysql_get_server_version () from G:\SOFT\MySQL\mysql-connector-c-6.1.0-win32\lib\libmysql.dll
No symbol table info available.
#3  0x00000001 in ?? ()
No symbol table info available.
#4  0x0028fc20 in ?? ()
No symbol table info available.
#5  0x6794482e in QSqlDatabase::open (this=0x28fdf8) at kernel\qsqldatabase.cpp:835
No locals.
#6  0x0040179e in qMain (argc=1, argv=0x3338e0) at ..\untitled24\main.cpp:17
        a = {<QGuiApplication> = {<QCoreApplication> = {<QObject> = {_vptr.QObject = 0xcd7e48 <vtable for QApplication+8>, static staticMetaObject = {d = {superdata = 0x0, stringdata = 0x6bb717c0 <qt_meta_stringdata_QObject>, data = 0x6bb718c0 <qt_meta_data_QObject>, static_metacall = 0x6b908eec <QObject::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x0, extradata = 0x0}}, d_ptr = {d = 0x333978}, static staticQtMetaObject = {d = {superdata = 0x0, stringdata = 0x6bc30700 <qt_meta_stringdata_Qt>, data = 0x6bc38e40 <qt_meta_data_Qt>, static_metacall = 0x0, relatedMetaObjects = 0x0, extradata = 0x0}}}, static staticMetaObject = {d = {superdata = 0x6bb7134c <QObject::staticMetaObject>, stringdata = 0x6bc45400 <qt_meta_stringdata_QCoreApplication>, data = 0x6bc455c0 <qt_meta_data_QCoreApplication>, static_metacall = 0x6b968828 <QCoreApplication::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x0, extradata = 0x0}}, static self = 0x28fdfc}, static staticMetaObject = {d = {superdata = 0x6bc45384 <QCoreApplication::staticMetaObject>, stringdata = 0xa38cdc0 <qt_meta_stringdata_QGuiApplication>, data = 0xa38d1c0 <qt_meta_data_QGuiApplication>, static_metacall = 0x9f5e1c4 <QGuiApplication::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x0, extradata = 0x0}}}, static staticMetaObject = {d = {superdata = 0xa383040 <QGuiApplication::staticMetaObject>, stringdata = 0xbff4c0 <qt_meta_stringdata_QApplication>, data = 0xbff740 <qt_meta_data_QApplication>, static_metacall = 0x7a11d8 <QApplication::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x0, extradata = 0x0}}}
        db = {static defaultConnection = 0x679696a5 <_ZStL6ignore+214> "qt_sql_default_connection", d = 0x33e648}
        __PRETTY_FUNCTION__ = "int qMain(int, char**)"
        w = {<QWidget> = {<QObject> = {_vptr.QObject = 0x28fe48, static staticMetaObject = {d = {superdata = 0x0, stringdata = 0x6bb717c0 <qt_meta_stringdata_QObject>, data = 0x6bb718c0 <qt_meta_data_QObject>, static_metacall = 0x6b908eec <QObject::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x0, extradata = 0x0}}, d_ptr = {d = 0x779371f5 <ntdll!WinSqmSetIfMaxDWORD+49>}, static staticQtMetaObject = {d = {superdata = 0x0, stringdata = 0x6bc30700 <qt_meta_stringdata_Qt>, data = 0x6bc38e40 <qt_meta_data_Qt>, static_metacall = 0x0, relatedMetaObjects = 0x0, extradata = 0x0}}}, <QPaintDevice> = {_vptr.QPaintDevice = 0x31b50df, painters = 65534, reserved = 0x778f38aa <ntdll!RtlImageNtHeader+1814>}, static staticMetaObject = {d = {superdata = 0x6bb7134c <QObject::staticMetaObject>, stringdata = 0xc05b00 <qt_meta_stringdata_QWidget>, data = 0xc06580 <qt_meta_data_QWidget>, static_metacall = 0x7dc112 <QWidget::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x0, extradata = 0x0}}, data = 0x778f34a2 <ntdll!RtlImageNtHeader+782>}, static staticMetaObject = {d = {superdata = 0xbfc060 <QWidget::staticMetaObject>, stringdata = 0x4051a4 <qt_meta_stringdata_Widget>, data = 0x4051c0 <qt_meta_data_Widget>, static_metacall = 0x401a34 <Widget::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x0, extradata = 0x0}}}
#7  0x00402c90 in WinMain@16 () at qtmain_win.cpp:113
        argc = 1
        argvW = 0x58d970
        argv = 0x3338e0
        exitCode = 92
#8  0x004033dd in main ()
No symbol table info available.