QT 操作数据库SQLite实例

#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();
}