#include "widget.h"

#include <QApplication>

#include <QtSql>

#include <QTextCodec>

#include <QDebug>

int main(int argc, char *argv[])

{

    QApplication a(argc, argv);

    QTextCodec::setCodecForTr(QTextCodec::codecForLocale());

    /*QStringList drivers = QSqlDatabase::drivers(); //获取支持的SQL驱动

    for( int i=0; i!=drivers.count(); i++ )

        qDebug() << "driver: " << drivers.at(i);

    */

    QSqlDatabase dbconn=QSqlDatabase::addDatabase("QSQLITE");    //添加数据库驱动

    dbconn.setDatabaseName("mytest.db");  //在工程目录新建一个mytest.db的文件

    if(!dbconn.open())

    {

        qDebug()<<"error";

    }

    QSqlQuery query(dbconn);//以下执行相关QSL语句

    //新建student表，id设置为主键，还有一个name项

    query.exec("create table student(id varchar,name varchar)");

    query.exec(QObject::tr("insert into student values(1,'李刚')"));

    query.exec(QObject::tr("insert into student values(2,'苹果')"));

    query.exec(QObject::tr("insert into student values(3,'葡萄')"));

    query.prepare("insert into student values(?,?)");

    QVariantList ids;

    ids << 4 << 5 << 6;

    query.addBindValue(ids);

    QVariantList names;

    names << "kevin" << "xiang" << "jie";

    query.addBindValue(names);

    if( !query.execBatch() )

        qDebug() << "Error: " << query.lastError();

    query.exec("update student set name='xiangjie' where id=5"); //更新

    query.exec("delete from student where id=6"); //删除

    //query.exec("select id,name from student where id>=2");

    query.exec("select * from student");

    while(query.next())//query.next()指向查找到的第一条记录，然后每次后移一条记录

    {

        int ele0=query.value(0).toInt();//query.value(0)是id的值，将其转换为int型

        QString ele1=query.value(1).toString();

        qDebug()<< query.at() <<  ele0<<ele1;//输出两个值

    }    

    query.seek(3);

    QSqlRecord record = query.record(); //获取当前行记录

    qDebug() << "id: " << record.value("id").toInt() << " name: " << record.value("name").toString();

    QSqlField field = record.field(1);  //获取索引字段

    qDebug() << "field name:" << field.name() << " field value:" << field.value().toString();

    query.exec(QObject::tr("drop table student")); //删除table

    //return a.exec();

}