SOLVED: Using MS SQL Server 2013 Database with QT

[M001]

Hallo, I'm trying to connect my MS SQL Server Database to my QT Projekt. This is my code:
@#include <QCoreApplication>
#include <QtSql/QtSql>
#include <QDebug>

int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);

QSqlDatabase db = QSqlDatabase::addDatabase("QODBC");
db.setHostName("(localdb)\\Projects");
db.setDatabaseName("PDB");
db.setUserName("DOMAIN\\user");
db.setPassword("");

if (!db.open()) {
   qDebug() << db.lastError().text();
   return 1;
}


if (!db.open()) {
   qDebug() << db.lastError().text();
   return 1;
}


return a.exec(&#41;;

} @

But im allways getting this error:
Microsoft ODBC Driver Manager / The Datasourcename could not be found, and there was no standard driver selected QODBC3: Unable to connect

I have created the Database with Visual Studio 2013.