Display Values from database to Qcombobox

xayn13

Hi ! I'm a newbie with QT and c++, I have been trying to display values from Qcombobox from the Database, but no avail. I was wondering if someone can take a look and help me.
Here's a section of my code

QSqlQuery query;
query.prepare("SELECT rep FROM Auth");
query.exec();
query.first();
QString a= query.value(0).toString();
ui->nnid->addItem(a);

Thank you

mrjj

Hi and welcome to the forums.

If you dont get anything in combobox
then i guess the SqlQuery dont get any results ?

update:
you could try

if ( ! query.first() )
qDebug() << "no record";

QString a= query.value(0).toString();
ui->nnid->addItem(a);

to see if it can position on first record.

xayn13

Thank you for taking the time to answer me, however that did not work as well. I honestly don't know what I'm doing wrong, because apart from this, I already have a Crud working.

mrjj

@xayn13

Did it show "no record" ?

or what happens ?

While you are not checking return values, it does look ok.

xayn13

Sorry I definitely forgot to mention that part.
no actually nothing showed up !!!

xayn13

actually nevermind, it worked ! thank you !!

mrjj

@xayn13
Super :)

For debugging help , its a good idea to do

QSqlQuery query;
query.exec(QString("xxx");
if (query.next())
{
// use it
} else {
    qDebug() << "SqLite error:" << query.lastError().text() << ", SqLite error code:" << query.lastError().number();
}

as it does report good stuff in case of something up with the query.

xayn13

that's more or less what I did !
Thank you though !!

eyllanesc

@xayn13 Another possible solution is to use QSqlQueryModel:

QSqlQueryModel *model = new QSqlQueryModel;
model->setQuery("SELECT rep FROM Auth");
ui->nnid->setModel(model);