Sort/filter model/view from database table!

[freecamellia]

See this interface and the following code, and be patient please! I hope in this once its clear.

!http://im10.gulfup.com/2011-12-03/1322954612301.png(test)!

@Widget::Widget()
{
// Connection
QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");
db.setDatabaseName("database");
bool opened = db.open();

// populate a QSqlTableModel with an entire sorted table from the database
tableModel = new QSqlTableModel(parent ,db);
tableModel->setTable("table"); // with 2 columns: col1 & col2
tableModel->setEditStrategy(QSqlTableModel::OnManualSubmit);
tableModel->sort(0, Qt::AscendingOrder);
tableModel->select();

//Set the tableModel in a proxyModel and set one column of the proxyModel in a listView
proxyModel = new QSortFilterProxyModel;
proxyModel->setSourceModel(tableModel);

ui->listView->setModel(proxyModel);
ui->listView->setModelColumn(0);

//When we just begin typing text in the lineEdit, the listView must display items begining whith the lineEdit value.
connect(ui->lineEdit, SIGNAL(textChanged(QString)),this , SLOT(filterChanged(QString)));

//When an listView item (col1 item) is clicked, his corresponding field in the other column (col2) is displayed in a textEdit
connect(ui->listView, SIGNAL(clicked(QModelIndex)),this , SLOT(itemClicked(QModelIndex)));
}

//Slots
void Widget::filterChanged(const QString &filter)
{
proxyModel->setFilterRegExp(QString("^%1").arg(filter));
}

void Widget::itemClicked(QModelIndex i)
{
int r = i.row();
QSqlRecord rec = tableModel->record(r);
QSqlField f = rec.field("col2");
QVariant v = f.value();
QString str = v.toString();
ui->textEdit->setText(str);
}@

Questions:
1/ Is this a convenience use of the model/view architecture?
2/ The problem with this code is that the filter don't work, i.e. when I type something in the lineEdit, the listView displays nothing.
3/ Advices?

thanks in advance

[goetz]

Your itemClicked method can be simplified:

@
void Widget::itemClicked(QModelIndex i)
{
int r = i.row();
QString str = proxyModel->data(proxyModel->index(r,1), Qt::DisplayRole);
ui->textEdit->setText(str);
}
@

The filter looks ok to me, one would have to test in a real application to see what's going wrong.

[freecamellia]

Thanks for your replay.

The data() method return a QVariant value, not QString. And I need the second column col2 instead of the first. So some modifications are required as follow:

@int r = i.row();
QVariant v = proxyModel->data(proxyModel->index(r,2), Qt::DisplayRole);
QString str = v.toString();
ui->textEdit->setText(str);@

but I have always the same problem with the filter, I don't find the solution and I am stopped now...

[goetz]

This code works for me:

create-qdndb.sql

@
CREATE TABLE qdntest (
col1 varchar(100) not null,
col2 varchar(100) not null
);

INSERT INTO qdntest VALUES( 'abc' ,'column 2 of abc');
INSERT INTO qdntest VALUES( 'aboc' ,'column 2 of aboc');
INSERT INTO qdntest VALUES( 'abzee' ,'column 2 of abzee');
INSERT INTO qdntest VALUES( 'qdn' ,'column 2 of qdn');
INSERT INTO qdntest VALUES( 'test' ,'column 2 of test');
INSERT INTO qdntest VALUES( 'what' ,'column 2 of what');
@

mainwindow.h

@

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QtGui/QDialog>

class QListView;
class QLineEdit;
class QTextEdit;
class QSqlTableModel;
class QSortFilterProxyModel;
class QModelIndex;

class MainWindow : public QDialog
{
Q_OBJECT

public:
MainWindow(QWidget *parent = 0);
~MainWindow();

protected slots:
void filterChanged(const QString &filter);
void itemClicked(const QModelIndex &index);

private:
QListView *listView;
QLineEdit *lineEdit;
QTextEdit *textEdit;
QSqlTableModel *tableModel;
QSortFilterProxyModel *proxyModel;
};

#endif // MAINWINDOW_H
@

mainwindow.cpp

@

#include "mainwindow.h"

#include <QListView>
#include <QLineEdit>
#include <QTextEdit>
#include <QSqlTableModel>
#include <QSortFilterProxyModel>
#include <QVBoxLayout>
#include <QSqlDatabase>

MainWindow::MainWindow(QWidget *parent)
: QDialog(parent)
{
QVBoxLayout *layout = new QVBoxLayout(this);

lineEdit = new QLineEdit;
layout->addWidget(lineEdit);

listView = new QListView;
layout->addWidget(listView);

textEdit = new QTextEdit;
layout->addWidget(textEdit);

QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");
db.setDatabaseName("/Users/volker/qdn.db");
db.open();

tableModel = new QSqlTableModel(this, db);
tableModel->setTable("qdntest");
tableModel->setEditStrategy(QSqlTableModel::OnManualSubmit);
tableModel->sort(0, Qt::AscendingOrder);
tableModel->select();

proxyModel = new QSortFilterProxyModel;
proxyModel->setSourceModel(tableModel);

listView->setModel(proxyModel);
listView->setModelColumn(0);

connect(lineEdit, SIGNAL(textChanged(QString)), this, SLOT(filterChanged(QString)));
connect(listView, SIGNAL(clicked(QModelIndex)), this, SLOT(itemClicked(QModelIndex)));

}

MainWindow::~MainWindow()
{
}

void MainWindow::filterChanged(const QString &filter)
{
proxyModel->setFilterRegExp(QString("^%1").arg(filter));
}

void MainWindow::itemClicked(const QModelIndex &index)
{
QString text = proxyModel->data(proxyModel->index(index.row(), 1), Qt::DisplayRole).toString();
textEdit->setPlainText(text);
}
@

main.cpp

@
#include <QtGui/QApplication>
#include "mainwindow.h"

int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow w;
w.show();

return a.exec();

}
@

qdntest.pro

@

#-------------------------------------------------

Project created by QtCreator 2011-12-04T22:06:13

#-------------------------------------------------

QT += core gui sql

TARGET = SqlProxyModelTest
TEMPLATE = app

SOURCES += main.cpp
mainwindow.cpp

HEADERS += mainwindow.h
@

[freecamellia]

Sorry, I tested it but the filter always don't work! when I type something in the lineEdit, the listView becomes empty.

[andre]

So, that seems reasonable to me if no item in the list matches the filter text. What is the actual problem?

[goetz]

So what didd you type in? Of course, there will only be items remaining, if you start your search with one of the letters a, q, t or w.

[freecamellia]

Yes, even if I type a, q, t or w, the listView becomes empty again.
It works for you?!

[goetz]

[quote author="freecamellia" date="1323086553"]Yes, even if I type a, q, t or w, the listView becomes empty again.
It works for you?![/quote]

Of course:

[quote author="Volker" date="1323033824"]This code works for me:[/quote]

[freecamellia]

Thank you for your helps during all this time.
Regards.

[freecamellia]

[quote author="Andre" date="1323085112"]So, that seems reasonable to me if no item in the list matches the filter text. What is the actual problem?[/quote]

[quote author="freecamellia" date="1322956485"]when I type something in the lineEdit, the listView displays nothing.
[/quote]

This is my problem.

[andre]

That only means that your filter filters out everything: no row matches whatever the filter was that was created based on what was typed in the line edit.

I have no way of checking how you implemented that, but based on the implementation shown in this topic:
@
void MainWindow::filterChanged(const QString &filter)
{
proxyModel->setFilterRegExp(QString("^%1").arg(filter));
}
@
the filter should match any item that starts with whatever you typed in the line edit.