Trouble with QSqlRecord class

daGenie

I am creating a database with SQLite and I am trying to insert information with the QSqlRecord class but it doesn't work at all. I created a class for the database called "DatabaseManager". This class contains a QSqlDatabase object which I manipulate to create my table. I successfully create the database using QSqlQuery:

bool DatabaseManager::createNamesTable() {

bool ret = false;
QSqlQuery query;

// db is the database object
if(db.isOpen()) {
ret = query.exec("CREATE TABLE names ("
"id INTEGER,"
"firstname VARCHAR(30),"
"lastname VARCHAR(30)"
")");
}

return ret;

}

Unfortunately, when I try to use the QSqlRecord class, nothing happens. It doesn't even give an error. This is the definition in the .cpp file of DatabaseManager.

void DatabaseManager::insertField(const QString &tableName, int pos, const QString &fieldName,
QVariant::Type type) {
db.record(tableName).insert(pos, QSqlField(fieldName, type));
}

And in the main(), I write:

int main(int argc, char** argv)
{
QCoreApplication app(argc, argv);

DatabaseManager db("New.db.sqlite");

if( db.createNamesTable()) {
db.insertField("names", 3, "places", QVariant::String); // here, i try to add a column called "places"
qDebug() << "Does names contain places? " << db.contains("names", "places");
}

app.exec();

}

I'm completely confused on what I'm doing wrong! Any form of help would be appreciated!

vittalonline

hi daGenie,

I think you missed this statement.

QSqlDatabase db = QSqlDatabase::addDatabase( "QSQLITE" );

This statement helps to get the already existed database connection object.

daGenie

[quote author="Vittal" date="1373873277"]hi daGenie,

I think you missed this statement.

QSqlDatabase db = QSqlDatabase::addDatabase( "QSQLITE" );

This statement helps to get the already existed database connection object.[/quote]

Thanks for the reply.

That statement is in the constructor of the DatabaseManager class but unfortunately, it still doesn't work.

vittalonline

ok friend ,

send error report.Database connection management is easiest programming in Qt ,so its not a big problem.I always help u.

daGenie

[quote author="Vittal" date="1373880559"]ok friend ,

send error report.Database connection management is easiest programming in Qt ,so its not a big problem.I always help u.[/quote]

Do you mean I should call the lastError().text() function and send the results? If that is the case, I have already tried that, and it returns an empty string which means "no error" I suppose.