QSqlQuery and SQL text field escape sequences

KroMignon

Hi all,

I need to create "partial" SQL requests which only contains the "value" part.
I some of those values there are text fields.
I known, QSqlQuery can handle this very nicely using prepare() and bindValue().
But is there a way to get the generated SQL query?

I just need the SQL query string, not to execute the query.
How can I achieve this?

Best regards

KroMignon

@VRonin Thank's a lot! You save my day.

In fact, it is easy, just setup a QSqlField, get the DB driver from QSqlDataBase, and call formatValue().

QSqlDataBase db = QSqlDatabase::addDatabase(...)
...
QSqlField f(QLatin1String(""), QVariant::String);
f.setValue("The string to be converted");
QString formatedValue = db->driver()->formatValue(f);

J.Hilk

@KroMignon lmgtfy:

ét voilà

KroMignon

QSqlQuery::lastQuery() is not working, it returns the SQL query with the place holders, not the full query!

VRonin

from qsqlresult.cpp

QString query = lastQuery();
if (d->binds == NamedBinding) {
        int i;
        QVariant val;
        QString holder;
        for (i = d->holders.count() - 1; i >= 0; --i) {
            holder = d->holders.at(i).holderName;
            val = d->values.value(d->indexes.value(holder).value(0,-1));
            QSqlField f(QLatin1String(""), val.type());
            f.setValue(val);
            query = query.replace(d->holders.at(i).holderPos,
                                   holder.length(), driver()->formatValue(f));
        }
    } else {
        QString val;
        int i = 0;
        int idx = 0;
        for (idx = 0; idx < d->values.count(); ++idx) {
            i = query.indexOf(QLatin1Char('?'), i);
            if (i == -1)
                continue;
            QVariant var = d->values.value(idx);
            QSqlField f(QLatin1String(""), var.type());
            if (var.isNull())
                f.clear();
            else
                f.setValue(var);
            val = driver()->formatValue(f);
            query = query.replace(i, 1, driver()->formatValue(f));
            i += val.length();
        }
    }

It's not trivial but you can probably achieve it without accessing the private API either

KroMignon

@VRonin Thank's a lot! You save my day.

In fact, it is easy, just setup a QSqlField, get the DB driver from QSqlDataBase, and call formatValue().

QSqlDataBase db = QSqlDatabase::addDatabase(...)
...
QSqlField f(QLatin1String(""), QVariant::String);
f.setValue("The string to be converted");
QString formatedValue = db->driver()->formatValue(f);