[SOLVED] About setting a QSqlTableModel to a QStringList

holygirl

If I want a column of values from the database to appear in a QComboBox, I use the model/view programming to achieve it with the code given below

@
QSqlTableModel m = new QSqlTableModel();
m->setTable("table");
m->setModelColumn(3);
m->select();

QComboBox *comboBox = new QCombobox();
comboBox->setModel(m);
@

I don't want a comboBox but I simply want to store the values in a QStringList and loop through each value to do something with it. My questions are:

Is it possible with a QStringList? Because I'm not able to set the model it as

@
QStringList stringList;
stringList.setModel();
@

If not QStringList, is it ok to use a QComboBox itself? If not, what are the other options?

maxoreli

You can do that:
@
QSqlTableModel m = new QSqlTableModel();
m->setTable("table");
m->setModelColumn(3);
m->select();

 QStringList stringList;
   for(int i = 0; i < m->rowCount(); i++)
    stringList.append( m->record(i).value(your_index_column).toString());

@

And your values is charged in stringList

qxoz

never mind

andre

I'd just skip using models at all, and use [[doc:QSqlQuery]] directly:

@
QSqlQuery query = QSqlQuery(db); //db is your database object
query.exec("SELECT MyColumnName FROM MyTableName"); //optionally add filtering or ordering using WHERE and ORDER BY clauses
QStringList results;
while(query.next()) {
results << query.value(0).toString();
}
@
The model/view architecture is there for putting data in views in a generic way. It is not all that suitable for other purposes. Other APIs are more suitable for that. If you find yourself directly manipulating QAbstractItemModel API while you're not building your own models and views, you are probably doing it wrong(TM).

maxoreli

have you tested my code?

maxoreli

have you tested my code?
[quote author="qxoz" date="1359542026"]never mind[/quote]

qxoz

Your code should work:
@QSqlTableModel *m = new QSqlTableModel();
m->setTable("table");
m->select();

 QStringList stringList;
   for(int i = 0; i < m->rowCount(); i++)
    stringList.append( m->record(i).value(your_index_column).toString());@

but Andre shows more optimal variant

holygirl

Thanks for the reply guys. Why I said I'm using a model is because I have been asked to use a model instead of direct SQL queries. I will however show both versions i.e. maxoreli and Andre's code, to my mentor and see which one I can use. I'll get back to you guys and tell you which one I finally used.

Thanks a lot!

holygirl

Hi again!

 Just an update to let y'all know that I went with Andre's solution. Using models became very complicated and resulted in many many lines of code. So yeah, I used QSqlQuery directly.

On the other hand, when I tried maxoreli's solution, I had

@
model = new QSqlQueryModel();
model->setQuery(s);
label->setText(model->record(0).toString();
@

and this gives me an error:

Use of undefined type QSqlRecord
Left of .toString must point to class/struct/union/generic type

Why?

qxoz

Add #include<QSqlRecord> on top of your source

holygirl

That did it! Thanks. I included QSqlQueryModel and was wondering why it isn't working. Thanks a lot.

qxoz

If still not works do following steps:

Build -> Clean All
Build -> Run qmake
Build -> Rebuild All

holygirl

Thank you. I had to edit the previous post cuz I thought you said include QSqlQueryModel and not QSqlRecord

holygirl

EDIT: Please ignore the following comment. There was a problem with my database and not my code.

Ok guys, I followed Andre's method and I'm not getting any errors. However, I'm not getting any output either. Here's the code

@
QSqlQuery query = QSqlQuery(db); //db is the database object
QString st = QString("SELECT TIME FROM SCHEDULE WHERE ID = %1").arg(str);
query.prepare(st);
query.exec();

QStringList strlist;

while(query.next())
{
strlist.append(query.value(0).toString());
qDebug()<<query.value(0).toString();
}
@

The qDebug does not display anything. Where am I going wrong? Please help.