Reading image from QSqlTableModel

[artwaw]

@gabor53 of course. Model's data() method returns QVariant, you can get QByteArray this way.

[gabor53]

This post is deleted!

[gabor53]

@artwaw
The delegate's paint looks like this:

void FixViewDelegate::paint(QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index) const {

I can get the index of the item from QModelIndex& index, but as there is no model, how can I get the QByteArray from the db (or model)?
Thank you.

[gabor53]

@artwaw
As I have no access to the model, is it OK to use a query to get the bytearray from the model?

[SGaist]

Index is your point of access to the model. See QModelIndex::data.

[gabor53]

@SGaist
I tried the following:

QVariant fixImg;

  fixImg = index.data (Qt::DisplayRole);

  QPixmap pixMap2;
  pixMap2 = fixImg.value<QPixmap>();

  qDebug() << "pixMap2 size: " << pixMap2.size ();
  qDebug() << "pixMap2 width: " << pixMap2.width ();

No error message, but the size is 0. Did I miss a step?
Thank you.

[SGaist]

Do you store a QPixmap in your model for that role ?

[gabor53]

It's a QByteArray.

[gabor53]

@SGaist
I ran

 QVariant fixImg(index.data (Qt::EditRole));

  qDebug() << "QVariant type: " << fixImg.type ();

and the result was
QVariant type: QVariant::QString

[jsulm]

@gabor53 said in Reading image from QSqlTableModel:

It's a QByteArray.

QByteArray of what? What and how are you storing in the DB? What is the data type of the corresponding column?

[gabor53]

@jsulm
QByteArray of the original image. The data type of that column is BLOB.

[raven-worx]

@gabor53
i asked in a post before:

QByteArray ba = fixModel->record (1).value ("Pic").toByteArray ();
qDebug() << ba.size() << ba;

in your delegates paint() method (if really a QByteArray is returned) do the following:

if( index.column() == NUMBER_OF_PIXMAP_COLUMN )
{
      QByteArray ba = index.data( ROLE_USED_IN_MODEL ).toByteArray();
     QPixmap pix;
        pix.loadFromData ( ba );
     painter->save();
         painter->translate( option.rect.topLeft() );
         painter->drawPixmap( pix );
     painter->restore();
}

I you should probably post your model code to avoid further guessing.

[VRonin]

• I don't like index.column() == NUMBER_OF_PIXMAP_COLUMN as it ties the delegate to a single model so I consider it bad design, view->setItemDelegateForColumn() should be used instead.
• index.data( ROLE_USED_IN_MODEL ) it's a QSqlTableModel so just delete ROLE_USED_IN_MODEL and use the default
• It's a QStyledItemDelegate so let's use style

void FixViewDelegate::paint(QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index) const {
QPixmap loadedImage;
loadedImage.loadFromData(index.data().toByteArray());
const QWidget *widget = option.widget;
QStyle *style = widget ? widget->style() : QApplication::style();
style->drawItemPixmap(painter,option.rect,Qt::AlignCenter,loadedImage);
}

[gabor53]

This post is deleted!

[gabor53]

@VRonin
Thank you. It runs without error, but paint nothing in the view.

[VRonin]

How do you save your image in the database? do you save it via Qt? can you show us the save part of the code?

[gabor53]

@VRonin
Sure. I also added

 qDebug() << "loadedImage size: " << loadedImage.size ();

and the result is
loadedImage size: QSize(0, 0)

I save the image via Qt like this:

#include "review.h"
#include "ui_review.h"

Review::Review(QWidget* parent) :
  QDialog(parent),
  ui(new Ui::Review) {
  ui->setupUi(this);

  connect(this, &Review::RecAdded, this, &Review::updateTable);

}

Review::~Review() {
  delete ui;
}

void Review::dispRev(QString sID, QString& name, QString& whatChosen, QString& fileNameChosen, QString& materialChosen, QString& colorChosen, QString& description, QDate& adoptDate, QString& SignedbyChosen, QString& history, QString& age, QString& notesTemp) {
  name = name.simplified ();
  description = description.simplified ();

  ui->ID_display_Label->setText (sID);
  ui->Name_Disp_Label->setText (name);
  ui->What_Display_Label->setText (whatChosen);
  ui->MadeOf_Disp_Label->setText (materialChosen);
  ui->Color_Disp_Label->setText (colorChosen);
  ui->textBrowser_Descr->setText (description);
  adoptDateStr = adoptDate.toString ("MM/dd/yyyy");
  ui->AdoptionDate_Disp_Label->setText (adoptDateStr);
  ui->SignedBy_Disp_label->setText (SignedbyChosen);
  ui->textBrowser_History->setText (history);
  ui->Age_Display_Label_2->setText (age);
  ui->textBrowser_Notes->setText (notesTemp);


  QPixmap pix2(fileNameChosen);
  int w = 0;
  int h = 0;
  w = ui->Image_Display_Label->width ();
  h = ui->Image_Display_Label->height ();
  ui->Image_Display_Label->setPixmap (pix2.scaled(w, h, Qt::KeepAspectRatio));

  QFile fileReview(fileNameChosen);

  if(fileReview.open (QIODevice::ReadOnly)) {
    fileByteArray = fileReview.readAll ();
  }

  nameReview = name;
  whatReview = whatChosen;
  fileNameReview = fileNameChosen;
  materialReview = materialChosen;
  colorReview = colorChosen;
  descriptionReview = description;
  adoptDateReview = adoptDate;
  SignedbyReview = SignedbyChosen;
  historyReview = history;
  sIDReview = sID;
  ageReview = age;
  notesReview = notesTemp;

}


void Review::on_pushButton_Add_to_DB_clicked() {

//    date = adoptDateReview.toString ("MM/dd/yyyy");
  qDebug() << "date in review.cpp: " << date;
  QSqlDatabase db = QSqlDatabase::addDatabase ("QSQLITE", "writedb");
  db.setDatabaseName (fileQstring);

  QSqlQuery querys(db);

  if(!db.open ())

  {
    qDebug() << "The database is not open (submit)!";
  } else {
    qDebug() << "The database is open (submit)!";
  }
  querys.prepare("INSERT INTO Items (ID, Name, Pic, Description, AdoptDate, History, Age, Notes, Color, Material, Signed, What) VALUES(:ID, :Name, :Pic, :Description, :AdoptDate, :History, :Age, :Notes, :Color, :Material, :Signed, :What)" );
  querys.bindValue (":ID", sIDReview);
  querys.bindValue (":Name", nameReview);
  querys.bindValue (":Pic", fileByteArray);
  querys.bindValue (":Description", descriptionReview);
  querys.bindValue (":AdoptDate", adoptDateStr);
  querys.bindValue (":History", historyReview);
  querys.bindValue (":Age", ageReview);
  querys.bindValue (":Notes", notesReview);
  querys.bindValue (":Color", colorReview);
  querys.bindValue (":Material", materialReview);
  querys.bindValue (":Signed", SignedbyReview);
  querys.bindValue (":What", whatReview);

  bool result = querys.exec ();

  if(!result) {
    qDebug() << "Error inserting into the main db!" << querys.lastError ();

    QMessageBox::warning (this, "Add to Database Warning", "<b><font size='16' color='red'>Error 1002: The Friend was not added to the database.");

  } else {
    qDebug() << "Entered FunctAdd OK loop.";

    QMessageBox::information (this, "Confirmation", "<b><font size = '16' color = 'green'>The Friend was added to the database.</font>");



    emit RecAdded ();
  }
}


void Review::on_pushButton_Fix_clicked() {
  Additem* mAdditem = new Additem(this);
  mAdditem->FixFriend (sIDReview, nameReview, whatReview, fileNameReview, materialReview, colorReview, descriptionReview, date, SignedbyReview, historyReview, ageReview, notesReview);


  mAdditem->show ();
}


void Review::updateTable() {
  qDebug() << "Entered updateTable!";
  MainWindow* mMainWindow = new MainWindow(this);

  mMainWindow->Addview ();
  mMainWindow->show ();
}

Data in the db is stored as BLOB.

[SGaist]

You don't do anything in case fileReview.open fails so you might be storing empty QByteArrays in your database.

[gabor53]

@SGaist
I tried to add a record and I got an error message:
The database is open (submit)!
Error inserting into the main db! QSqlError("", "Parameter count mismatch", "")

I'm not sure this has anything to do with the original issue.
I checked a Pic field in the db using DB Browser and there is binary data in the Pic column.
I also made the following changes:

 if(loadedImage.loadFromData (index.data ().toByteArray ()) != true) {
    qDebug() << "Fiximage not loaded";
  } else {
    qDebug() << "Fiximage IS loaded";
  };
  

The result was Fiximage not loaded

[VRonin]

Error inserting into the main db! QSqlError("", "Parameter count mismatch", "")

I'm not sure this has anything to do with the original issue

It does.

SQLite some/all of Qt's SQLite drivers do not support named binding and apparently Qt is not smart enough to go around it seamlessly.

use positional binding instead, see http://doc.qt.io/qt-5/qsqlquery.html#approaches-to-binding-values

You should use the ? version instead of the :id version.

You can check what your database can do using db.driver()->hasFeature() in your case db.driver()->hasFeature(QSqlDriver::NamedPlaceholders) will return false

EDIT:

@SGaist is right, corrected my post