QT +=sql

#include "widget.h"#include <QApplication>#include <QtSql/QSqlDatabase>#include <QtSql/QSqlQuery>#include <QDebug>int main(int argc, char *argv[]){    QApplication a(argc, argv);    Widget w;    w.show();    int index=0;    //连接数据库    QSqlDatabase db = QSqlDatabase::addDatabase("QOCI");    db.setPort(1521);    db.setHostName("ip");    db.setDatabaseName("dbname");    db.setUserName("username");    db.setPassword("pwd");    if (db.open()) {        qDebug()<< "RIGHT";    }else{        qDebug()<< "ERROR";        return 0;    }    QVariantList* pVarList = new QVariantList[3];    for ( index = 0; index < 3; index++ )            pVarList[index].clear();    QSqlQuery query("SELECT id,name from user where rownum<=6");    while (query.next())    {        for ( index = 0; index < 3; index++ )            pVarList[index] <<query.value(index);    }    qDebug()<< pVarList[2].value(1).toString();    qDebug()<< "read over";    return a.exec();}