How to set data (Qt::UserRole) into QSqlQueryModel column? - c++

Question

I have QSqlQueryModel that handling data , im trying to set Qt::UserRole to column
but i can’t figure a way to do it i have implement the data method :
basically what i want is to hide the Qt::DisplayRole of ndex.column() 4 and set it to Qt::UserRole
QVariant MyListSqlModel::data(const QModelIndex &index, int role) const
{
QVariant value = QSqlQueryModel::data(index, role);
QVariant valueEmpty = "";
int j = index.column();
if (value.isValid() && role == Qt::DisplayRole && j== 4 )
{
QModelIndex LinkIndex = QSqlQueryModel::index(index.row(),4);
setData(LinkIndex,value,Qt::UserRole); // this is not working and gives me erorr
return valueEmpty;
}
else
{
return value;
}
}
it give me this error that i know what it is the implement method is not const
error C2662: 'MyListSqlModel::setData' : cannot convert 'this' pointer from 'const MyListSqlModel' to 'MyListSqlModel&'
but what is the right way to do it ?

Answer 1

As I understand from the code you want to ignore the Qt::DisplayRole of the column 4. In that case you don't have to deal with the UserRole but just return empty QVariant
QVariant MyListSqlModel::data(const QModelIndex &index, int role) const
{
if(index.column() == 4 && role == Qt::DisplayRole)
return QVariant();
//else process the data in ususal way
}
Please correct me if I misunderstood the question
edit
Thanks for the comment. I have started myself using custom roles for my models. The workflow goes like this:
Define a custom user role in the header
enum MyDataRoles {
MyDisplayRole = Qt::UserRole + 10
}
Now for the setData I am using a snippet from here.
And for getting the data you can use snippet from here. You just have to check for the MyDisplayRole
I hope that helps :)