QSqlTableModel set Integer data to NULL

[lynnH]

I have a sql table with a column of type integer allowing null values and I use a QSqlTableModel to manipulate its data.

I am facing the following problem: I want to insert a Null value using the QSqlTableModel setData function. When I do this, QSqlTableModel translates my Null into 0, its default value (Qt QTBUG-1512), which is not what I want (0 has a specific meaning in my application).

How can I set a null value?

Any hint will be greatly appreciated.

[mcosta]

HI,

I'm working with Qt 4.7.1 on Windows XP and for me it works fine.

This Code


QString connName;

QString fileName = QFileDialog::getSaveFileName (this, tr ("Create DB"));
if (!fileName.isEmpty ()) {
bool result = false;

QSqlDatabase db = QSqlDatabase::addDatabase ("QSQLITE");
db.setDatabaseName (fileName);

result = db.open ();
if (!result) {
qWarning () << "Error in db.open():" << db.lastError ().text();
return;
}
connName = db.connectionName ();

db.exec ("CREATE TABLE T_PDC ("
"val1 INTEGER NOT NULL, "
"val2 INTEGER)");

QSqlRecord record = db.record ("T_PDC");

QModelIndex idx;

QSqlTableModel model (this, db);
model.setTable ("T_PDC");
model.setEditStrategy (QSqlTableModel::OnManualSubmit);
model.select ();

int row;
for (int i = 0; i < 5; ++i) {
row = model.rowCount ();
qDebug () << "model.rowCount() = " << row;

result = model.insertRows (row, 1);
if (!result) {
qWarning () << "Error in model.insertRow () :" << model.lastError ().text ();
break;
}
else
qDebug () << "model.insertRow(): SUCCESS";

idx = model.index (row, 0);
if (!idx.isValid ()) {
qWarning () << "Invalid Index (" << row << ", 0)";
break;
}
model.setData (idx, i);

idx = model.index (row, 1);
if (!idx.isValid ()) {
qWarning () << "Invalid Index (" << row << ", 0)";
break;
}

if (i % 2)
result = model.setData (idx, 10 * (i + 1));
else
result = model.setData (idx, QVariant());

if (!result) {
qWarning() << "Error in model.setData ():" << model.lastError ().text ();
break;
}
}

result = model.submitAll ();
if (!result) {
qWarning () << "Error in model.submitAll() :" << model.lastError ().text ();
}
db.close ();
}
QSqlDatabase::removeDatabase (connName);


produce this result

6271

However consider to use QSqlRecord for obtain more compact code


int row;
QSqlRecord record = db.record (model.tableName ());
for (int i = 0; i < 5; ++i) {
row = model.rowCount ();
qDebug () << "model.rowCount() = " << row;

record.setValue (0, i);
if (i % 2)
record.setNull (1);
else
record.setValue (1, 10 * (i + 1));

model.insertRecord (row, record);
}

[lynnH]

Thanks for answering. Unfortunately I am using Qt 4.5.3 and this is not working. I tried to set the value directly with the QSqlRecord.

Is it an issue corrected in Qt 4.7 or do I have a chance with Qt 4.6?