How to get data from sqlquery that result 3 columns in a row and show only 1 Colum and use the other columns data

umen242

hello all
im using QSqlQueryModel subclass to excute sql querys and popolate them to tableview
now i have simple sql query that results 3 coulms / fields in arow that invoked in the QSqlQueryModel subclas like this :
@

QString query_local = "SELECT foo1,foo2,foo3 FROM tbl" ;
QSqlQueryModel::setQuery(query_local, queryDB);
if (lastError().type() != QSqlError::NoError)
{
QString err = lastError().text();
}
@

now later i set this to show me only foo3 in the table view that contains 1 column

@QSqlQueryModel::removeColumns(0,2);@

what i need is that the data from foo1 and foo2 and set in the the UserRole of each row in the tableview ( i have itemDelegate of the tableView ) and show in the display only foo3
how can it be done ?

Lykurg

Create your own model. Subclass QSqlQueryModel and reimp QSqlQueryModel::data(). If role is Qt::MyMagicFoo1 then use e.g. @foo1Idx = index.sibling(index.row(), 0);
// data of foo1
index.data(Qt::DisplayRole);@

EDIT: where 0 is the column of foo1 sql position.

umen242

hi
Thanks for the replay but i didnt understand it .
in the data subclass method i did :
@ QVariant value;
int c = index.column();
int r = index.row();

value = QSqlQueryModel::data(index, role);
QString s = value.toString();
if(role == Qt::DisplayRole)
{
value = QSqlQueryModel::data(index, role);
QString s = value.toString();
}
if(c ==2)
{
return value;
}
value ="";
return value;@

but it still show me in the result 3 columns , and only in the third the display
i dont what to display 3 columns only one

andre

The way I see it, you have two options:

Just hide the columns you don't want to see in the view. [[doc:QTableView]] supports the hideColumn(int column) method for that.

Use a [[doc:QSortFilterProxyModel]] to hide the columns you don't want, by subclassing that class and reimplementing the filterAcceptsColumn method to return false for the columns you want to hide.

umen242

hi and thanks for the replay i tryed to use hideColumn but it didnt work

@m_pPlayListMiniItemDelegate =new PlayListMiniItemDelegate(this);
ui->PlayListMini_tableView->setSelectionBehavior(QAbstractItemView::SelectRows);
ui->PlayListMini_tableView->setSelectionMode(QAbstractItemView::SingleSelection);
ui->PlayListMini_tableView->setItemDelegate(m_pPlayListMiniItemDelegate);
ui->PlayListMini_tableView->setAlternatingRowColors(true);
ui->PlayListMini_tableView->setModel(PlayListMiniSqlModel::instance());
ui->PlayListMini_tableView->hideColumn(0);
ui->PlayListMini_tableView->hideColumn(1);@

i want to avoid to add yet another model to the stack

andre

You mean that even after calling hideColumn, it is still visible in your view?

umen242

yes , but i implementing the QSortFilterProxyModel now i hope it will work finally ...

andre

Well, that would be a bug in Qt. If you could create a minimal simple, self-contained example that has this behaviour, then please share that.

umen242

will do , it will take time to build complex GUI as sample . but i will

andre

Please keep it as simple as possible when creating a sample. Less is more in these cases!

umen242

sure , by the way the filter proxy worked . thanks!

umen242

Hi but now i have another problem , in the proxy model
i set to filter the 2 first columns like this :
@bool PlayListMiniSortFilterProxyModel::filterAcceptsColumn(int source_column, const QModelIndex& index) const
{
//qDebug() << "filterAcceptsColumn(): column = " << source_column ;
if(source_column ==2)
return QSortFilterProxyModel::filterAcceptsColumn(source_column,index);
return false;
}@

and in the PlayListMiniSqlModel ( its the QSqlQueryModel im using in the table)
when i try to get the display string of the hidden 2 columns i only get the 3 column .
@QVariant PlayListMiniSqlModel::data(const QModelIndex &index, int role) const
{

QVariant value;

int c = index.column(); //HERE IT ONLY SHOW ME 2 , NEVER 0 and 1
int r = index.row();

value = QSqlQueryModel::data(index, role);
QString s = value.toString();
if(role == Qt::DisplayRole)
{
value = QSqlQueryModel::data(index, role);
QString s = value.toString();
}

return value;
}@

where in the model i can get the hidden column data ?

umen242

im using QSortFilterProxyModel to filter column that im getting from QSqlQueryModel model but becose the filterAcceptsColumn method is const "all the way" i have problem to set Qt::UserRole data in the right index . how can i overcome this?

@bool MiniSortFilterProxyModel::filterAcceptsColumn(int source_column, const QModelIndex& index) const
{
QVariant tmp ;
if(source_column ==0)
{

        setRowid(index.data(Qt::DisplayRole));

// here im getting compilation error
//: error C2678: binary '=' : no operator found which takes a left-hand operand of type 'const QString' (or there is no acceptable conversion)
m_rowId = index.model()->data(index,Qt::DisplayRole).toString();
return false;
}
else if(source_column ==1)
{
setYTid(index.data(Qt::DisplayRole));
return false;
}
else if(source_column ==2)
{

        setNewData(index);
        return QSortFilterProxyModel::filterAcceptsColumn(source_column,index);
    }
    return false;
}


void MiniSortFilterProxyModel::setRowid(QVariant rowId) const 
{

// here also compilation error:
m_rowId = rowId.toString();
}

void MiniSortFilterProxyModel::setYTid(QVariant ytId) const 
{

/ here also compilation error:
m_ytId = ytId.toString();
}

void MiniSortFilterProxyModel::setNewData(QModelIndex& index) const 
{

// here also compilation error:
//error C2511: 'void MiniSortFilterProxyModel::setNewData(QModelIndex &) const' : //overloaded member function not found in 'MiniSortFilterProxyModel'
QVariant data = m_rowId+"_"+m_ytId;
index.model()->setData(index,data,Qt::UserRole);
}
@

andre

[quote author="umen242" date="1333355148"]Hi but now i have another problem , in the proxy model
i set to filter the 2 first columns like this :
@bool PlayListMiniSortFilterProxyModel::filterAcceptsColumn(int source_column, const QModelIndex& index) const
{
//qDebug() << "filterAcceptsColumn(): column = " << source_column ;
if(source_column ==2)
return QSortFilterProxyModel::filterAcceptsColumn(source_column,index);
return false;
}@

and in the PlayListMiniSqlModel ( its the QSqlQueryModel im using in the table)
when i try to get the display string of the hidden 2 columns i only get the 3 column .
@QVariant PlayListMiniSqlModel::data(const QModelIndex &index, int role) const
{

QVariant value;

int c = index.column(); //HERE IT ONLY SHOW ME 2 , NEVER 0 and 1
int r = index.row();

value = QSqlQueryModel::data(index, role);
QString s = value.toString();
if(role == Qt::DisplayRole)
{
value = QSqlQueryModel::data(index, role);
QString s = value.toString();
}

return value;
}@

where in the model i can get the hidden column data ?[/quote]

That sounds logical to me. The data() method will be called by the view or proxy model on top of the model. That object will (as much as possible) only query for the items it needs. In this case, that would be column 2, not column 0 or 1, as your proxy hides these. Why do you expect this method to be called for all cells, even the ones you're not showing?

andre

[quote author="umen242" date="1333364703"]im using QSortFilterProxyModel to filter column that im getting from QSqlQueryModel model but becose the filterAcceptsColumn method is const "all the way" i have problem to set Qt::UserRole data in the right index . how can i overcome this?
[/quote]
I fail to understand why you'd need to modify the model from your filterAcceptsColumn() implementation.

umen242

very simple , sorry im not native English speaker so the semantics are wrong (most of the time..).
what im trying to do is very simple ( very simple in the logic of it )

run sql query that returns 3 columns in each row ("select foo1,foo2,foo3 from tbl")
use the data from column 1 and 2 ( concat the 2 strings )
set it to column 3 Qt::UserRole placeholder ( i need it for later use ) that in the end becomes the only row that is displayed
4 this is for each row / record that returns from the sql query

andre

OK. You don't need to modify the model at all for that. In either your base model or the proxy model, I would just reimplement the data method to return the right value for your Qt::UserRole for the column you're after. The filterAcceptsColumn method has nothing to do with that.

umen242

well i have reimplement the data method in the QSqlQueryModel
it looks like this :
@QVariant MiniSqlModel::data(const QModelIndex &index, int role) const
{
QVariant value;
int c = index.column(); //HERE IT IS ALWAYS == 2
int r = index.row();
value = QSqlQueryModel::data(index, role);
QString s = value.toString();
if(role == Qt::DisplayRole)
{
value = QSqlQueryModel::data(index, role);
QString s = value.toString();
}

return value;
}@

the problem is that im getting only the last column (2) and i dont have the data of the other 2 .
the only place i managed to catch the data of the first 2 columns (0,1) is in the filterAcceptsColumn method of the proxy .

i missing here something small .. i feel i realy close to solve this . ( already 5 days .. )

andre

Of course! Your proxy model only has one column! That's what you wanted to achieve, after all...
Your source model will still have all three columns, so you can still query these from the data method of proxy model.

Edit:
I would do something like this:
@
MyProxyModel::data(const QModelIndex& index, int role) const
{
if (!sourceModel())
return QVariant(); //we don't do useful things without a source model

if (index.column() == 0 && role == Qt::UserRole) {
//get the merged data from the underlying model
QModelIndex sourceIndex = mapToSource(index);
if (!sourceIndex.isValid())
return QVariant(); //you never know, right?

QModelIndex col1Index = sourceModel()->index(sourceIndex.row(), 0, sourceIndex.parent());
QString column1 = col1Index.data(Qt::DisplayRole).toString();
QModelIndex col2Index = sourceModel()->index(sourceIndex.row(), 1, sourceIndex.parent());
QString column2 = col1Index.data(Qt::DisplayRole).toString();

QString result = column1 + " - " + column2;
return QVariant(result);

}
return QSortFilterProxyModel(index, role);
}
@

Note: the above is untested, just typed into the editor directly.

umen242

no its the opposite, the data function is in the QSqlQueryModel.
i dont understand this :
@"...so you can still query these from the data method of proxy model...."@

how ? where ?

do you mean i need to implement the data method of the proxy ?