Load Image From Db Problem

[VRonin]

@M4RZB4Ni said in Load Image From Db Problem:

i think problem is converting from table(IMAGE DATATYPE) TO byte array !

are you using image as field type in your database? if so you shouldn't, it's deprecated and will be removed (see https://msdn.microsoft.com/en-us/library/ms187993.aspx). use varbinary(max) instead.

Also, you should use QImage instead of QPixmap.

Qt provides four classes for handling image data: QImage, QPixmap, QBitmap and QPicture. QImage is designed and optimized for I/O, and for direct pixel access and manipulation, while QPixmap is designed and optimized for showing images on screen. QBitmap is only a convenience class that inherits QPixmap, ensuring a depth of 1. Finally, the QPicture class is a paint device that records and replays QPainter commands.

[M4RZB4Ni]

@VRonin
yes i use IMAGE because when i use VABBINARY(MAX) when i want save image
program show error
"Cant Convert varchar datatype to VARBINARY(MAX)!
and i should Use IMAGE datatype!

[VRonin]

How do you save it?

You should definitely use VARBINARY:

From Microsoft, page linked above:

IMPORTANT! ntext, text, and image data types will be removed in a future version of SQL Server. Avoid using these data types in new development work, and plan to modify applications that currently use them. Use nvarchar(max), varchar(max), and varbinary(max) instead.

[M4RZB4Ni]

@M4RZB4Ni
this is all of my codes:
see it and if you can correct it
.h file:

QImage *pix;
        QImage originalPixmap;
        QPixmap outPixmap;
        QPixmap pxp;
        QGraphicsPixmapItem pixItem;
        QByteArray inByteArraye;
        QByteArray outByteArray;

.cpp file:

void Medical_Records::shootScreen()
{
    QScreen *screen = QGuiApplication::primaryScreen();
    if (const QWindow *window = windowHandle())
        screen = window->screen();
    if (!screen)
        return;

  originalPixmap=ui->graphicsView_2->grab().toImage();
    updateGraphicView();

}
void Medical_Records::initalizeVarables()
{
         shootScreen();
        QBuffer inBuffer( &inByteArraye );
        inBuffer.open(QIODevice::WriteOnly);
        originalPixmap.save(&inBuffer,"PNG");
}


void Medical_Records::readSkeletonPic()
{
    moveToThread(readSkeletonPicThread);
  readSkeletonPicQry.exec("SELECT SskeletonPic FROM Patient_File WHERE SmeliCode='"+seMcode+"'");
    readSkeletonPicQry.next();
    outByteArray = readSkeletonPicQry.value(0).toByteArray();
    //outPixmap = QPixmap();
    originalPixmap.loadFromData(outByteArray,"PNG");
    qDebug() << "outByteArray :" << outByteArray.size();
    qDebug() << "outByteArray :" << originalPixmap.size();
    outPixmap.fromImage(originalPixmap.fromData(outByteArray,"PNG"));
    scene->addPixmap(outPixmap);
    ui->graphicsView_2->setScene(scene);
    qDebug() << readSkeletonPicQry.exec();
    readSkeletonPicThread->start();
}

[VRonin]

i don't get the threading thing but it's probably not the point here. where did you get the
"Cant Convert varchar datatype to VARBINARY(MAX)" error?

[M4RZB4Ni]

@VRonin
when i want insert image into database after capture screenshot

[VRonin]

Can you post that code please?

[M4RZB4Ni]

@VRonin
yes of course
thanks so much

this is code :

void Medical_Records::initalizeVarables()
{

        shootScreen();
        QBuffer inBuffer( &inByteArraye );
        inBuffer.open(QIODevice::WriteOnly);
        originalPixmap.save(&inBuffer,"PNG");
}
void Medical_Records::submitWithScreenShot()
{

  initalizeVarables();
    QSqlQuery sql;
    sql.exec("UPDATE Patient_File SET SskeletonPic='"+inByteArraye+"' WHERE SmeliCode='"+seMcode+"';");
}

[VRonin]

yep, you should check QSqlQuery::bindValue

sql.prepare("UPDATE Patient_File SET SskeletonPic= :skp  WHERE SmeliCode= :smc");
sql.bindValue(":skp",inByteArraye);
sql.bindValue(":smc",seMcode);
sql.exec();

this also prevents SQL Injection. You should never really use unescaped input directly to build the query string

[M4RZB4Ni]

@VRonin
thanks but my problem is in Load image not save it!
Thank a lot My Friend :)

[VRonin]

make the field varbinary(max), save it that way and the code you have will work, no changes needed on the load part

image in SQL server is a fixed length string. it has nothing to do with images

[Kutyus]

Hi!
The same problem, you could solve?
Thanks

[VRonin]

@Kutyus

Summary of the above:

• in the database use the type VABBINARY not IMAGE
• use QSqlQuery::bindValue instead of string concatenation to build your query

[Kutyus]

@VRonin Thank you for reply, but my problem is the load image from database, please see my another question:
QT 5.8 image from database error