Parse array fields from PostgreSQL

oleg.meleshko

Hello to everyone!

Question: is it possible to convert/parse postgreSQL array field types into QList? Or I have to do that manually from QString which I'm getting right now?

Thank you in advance!

mcosta

Hi e welcome to the devnet,

could you post an example of how you handle that field now??

oleg.meleshko

QSqlQuery neurons;
neurons.exec("SELECT * FROM neurons");
while(neurons.next()) {
qDebug() << neurons.value("weights"); // QVariant(QString, "{0, 0, 255, 0, 255 ... }")
}

In PostgreSQL I have this field as int[]. So as you may see it's parsed as QString.
Question is how I can convert it correctly to be QList. Or I have to parse such QString manually?

mcosta

@oleg.meleshko said:

Or I have to parse such QString manually?

IMO yes,

the default for unsupported field_type is to return QString
SO you shoud do something like

QString myStr = neurons.value("weights").toString();
QStringRef sref (myStr, 1, myStr.length() - 2); // Remove braces
QVector<QStringRef> v = sref.split(",");
QList<int> l;
for (const QStringRef &r: v) {
  l << r.toInt();
}

oleg.meleshko

Ok, got it, thank you so much!

mcosta

@oleg.meleshko said:

Ok, got it, thank you so much!

You're welcome