Qt存储图片到数据库&&从数据库读取图片

使用Qt将图片存储到sqlite

my_sql::my_sql(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::my_sql)
{
    ui->setupUi(this);
    connect(ui->pushButton,SIGNAL(clicked()),this,SLOT(slot_StoreSql()));//选择图片上传到数据库
    connect(ui->pushButton_2,SIGNAL(clicked()),this,SLOT(slot_redImag()));//从数据库获取图片并显示
    //判断文件是否存在
    isFile(DATABASEPATH);

}

bool my_sql::isFile(QString strPath)
{
    QFile file(strPath);
    if(file.exists())
    {
       qDebug()<<"数据库文件存在";
       m_Base = dataBase::Instance(DATABASEPATH);
       return true;
    }
    else
    {
        qDebug()<<"数据库文件不存在";
        m_Base = dataBase::Instance(DATABASEPATH);
        QString strSql("create table if not exists imagetable(filename TEXT,imagedata BLOB)");
        m_Base->createTable(strSql);
        return false;
    }
}

void my_sql::slot_StoreSql()
{

    qDebug()<<"读取图片并保存数据库";
    imagPath = QFileDialog::getOpenFileName(this,"图片","C:\\Users\\lanti\\Pictures","(*.jpg *.jpeg *.png)");
    qDebug()<<imagPath;
    ui->label->setPixmap(QPixmap(imagPath));
    QString insertntoSql = "insert into imagetable(filename,imagedata) values( \"%1\",:imagedata)";
    m_Base->insertnto(insertntoSql,imagPath);

}

void dataBase::insertnto(QString Sql,QString strImag)
{
    db.open();
    if(!db.open()) {
        qDebug()<<"Failed to connect to root mysql admin";
    }
    else {
        qDebug()<<"open success!";
    }

    QFile * file=new QFile(strImag); //fileName为二进制数据文件名
    file->open(QIODevice::ReadOnly);//设置为只读模式
    QByteArray data = file->readAll();//将数据转换为QByteArray类型存储到数据库中
    file->close();
    
     QSqlQuery query;
     Sql = QString(Sql).arg(file->fileName());
     qDebug()<<Sql<<"------------------";
     query.prepare(Sql);
     query.bindValue(":imagedata",data);
     if(!query.exec())
     {
         printf("insert error");
         printf(query.lastError().text().toLocal8Bit().data());//若不成功，打印错误
         printf("n");
     }
     else
     {
         printf("insert ok");
     }
     db.close();
}

void my_sql::slot_redImag()
{
    QString m_image("C:\\temp\\666.jpg");
    QString Sql="select * from imagetable where filename = \"%1\"";
    QImage image = m_Base->selectImag(Sql,imagPath);
    image.save(m_image);
    ui->label_2->setPixmap(QPixmap(m_image));
}

QImage dataBase::selectImag(QString Sql, QString strImag)
{
    db.open();
    if(!db.open()) {
        qDebug()<<"Failed to connect to root mysql admin";
    }
    else {
        qDebug()<<"open success!";
    }
    QImage img;
    Sql = QString(Sql).arg(strImag);
    qDebug()<<Sql<<"***************";
    QSqlQuery query(Sql);
    if(!query.exec(Sql))
    {
    qDebug()<<"select "<<query.lastError().text();
    }
    while(query.next())
    {
        QString code = query.value(0).toString();
        QByteArray bytes = query.value(1).toByteArray();
        QBuffer buffer(&bytes);
        buffer.open(QIODevice::ReadOnly);
        QImageReader reader(&buffer,"JPG");
        img = reader.read();
        //img.save("D:/Images/666.jpg");
    }
    db.close();
    return img;
}