QSql - incomplete type 'struct QVariant'

Spent all day Friday and today looking at examples and can't spot what I'm doing wrong. Based on the error I feel like it's got to be something fundamental. I've reproduced the error below.

Code:

---

#include <QtCore/QCoreApplication>
#include <QSqlDatabase>
#include <QSqlError>
#include <QSqlQuery>
#include <QDir>
#include <QFile>
#include <QDebug>
 
int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
 
    QSqlQuery q;
    bool ret=false;
 
    QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");
 
    QString strDBFile(QDir::home().path());
    strDBFile.append(QDir::separator()).append("my.db.sqlite");
    strDBFile = QDir::toNativeSeparators(strDBFile);
    db.setDatabaseName(strDBFile);
 
    if(db.isOpen())
    {
        ret=q.exec("create table WTF(ID INT, NAME VARCHAR(20))");
        if(ret)
        {
            ret=q.exec("insert into WTF values(1, 'your mom')");
 
            if(ret)
            {
                q.exec("select * from WTF;");
 
                if(q.next())
                {
                    qDebug()<<q.value(0).toString();
                }
            }
        }
    }
 
    return a.exec();
}

---

Code:

---

C:/Documents and Settings/ald/My Documents/SQLStub/SQLStub-build-desktop/../SQLStub/main.cpp:36: error: invalid use of incomplete type 'struct QVariant'
 
c:\Qt\2010.04\qt\include/QtCore/../../src/corelib/kernel/qobject.h:66: error: forward declaration of 'struct QVariant'

---

Quote:

---

Originally Posted by UltramaticOrange

Code:

---

C:/Documents and Settings/ald/My Documents/SQLStub/SQLStub-build-desktop/../SQLStub/main.cpp:36: error: invalid use of incomplete type 'struct QVariant'
 
c:\Qt\2010.04\qt\include/QtCore/../../src/corelib/kernel/qobject.h:66: error: forward declaration of 'struct QVariant'

---

---

You need to add

Code:

---

#include <QVariant>

---

I think, it is better to create QSqlQuery object after opening database connection.

Like I said, missing something fundamental. Thanks. I'm going to go /headdesk in the corner now.

QSqlQuery is defined with a much more narrow scope (and after db is opened) in the real application.