Releasing database file with QSqlDatabase

[cia.michele]

Thanks wysota, I trying to do what you say, but I think didn't understand so much.
I try to do it in this way, is the correct way you sayd?

void myThread1::createDB(){
    nomeDB=QString("R%2_Prova%1.s3db").arg(idProva).arg(nrampa);
    QSqlDatabase::addDatabase("QSQLITE",nomeDB);
    QSqlDatabase(nomeDB).setDatabaseName(nomeDB);
    if (!QSqlDatabase(nomeDB).open()){
        msg.setText(QSqlDatabase(nomeDB).lastError().text());
        msg.show();
    }else{
        QSqlDatabase(nomeDB).exec("create table test (campo int)");
    }
}
 
void myThread1::execCmd(QString cmd){
 
    if (!QSqlDatabase(nomeDB).open()){
        msg.setText(QSqlDatabase(nomeDB).lastError().text());
        msg.show();
    }else{
        QSqlDatabase(nomeDB).exec(cmd);
    }
    QSqlDatabase(nomeDB).close();
 
}

void myThread1::createDB(){
    nomeDB=QString("R%2_Prova%1.s3db").arg(idProva).arg(nrampa);
    QSqlDatabase::addDatabase("QSQLITE",nomeDB);
    QSqlDatabase(nomeDB).setDatabaseName(nomeDB);
    if (!QSqlDatabase(nomeDB).open()){
        msg.setText(QSqlDatabase(nomeDB).lastError().text());
        msg.show();
    }else{
        QSqlDatabase(nomeDB).exec("create table test (campo int)");
    }
}

void myThread1::execCmd(QString cmd){

    if (!QSqlDatabase(nomeDB).open()){
        msg.setText(QSqlDatabase(nomeDB).lastError().text());
        msg.show();
    }else{
        QSqlDatabase(nomeDB).exec(cmd);
    }
    QSqlDatabase(nomeDB).close();

}

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I got this error:

'QSqlDatabase::QSqlDatabase(const QString&)' is protected

In which way I could address the database passing the connection name?

Thanks for your time

Michele

[wysota]

QSqlDatabase::database() retrieves a handler to the database.

QSqlDatabase::addDatabase("QSQLITE", nomeDB);
{
  // ...
  QSqlDatabase db = QSqlDatabase::database(nomeDB); // a local variable, not a class member
  db.exec(cmd);
  db.close();
}
QSqlDatabase::removeDatabase(nomeDB);

QSqlDatabase::addDatabase("QSQLITE", nomeDB);
{
  // ...
  QSqlDatabase db = QSqlDatabase::database(nomeDB); // a local variable, not a class member
  db.exec(cmd);
  db.close();
}
QSqlDatabase::removeDatabase(nomeDB);

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[cia.michele]

Thanks a lot wysota!
Now it's RUN!

This is the definitive code

void myThread1::createDB(){
    nomeDB=QString("R%2_Prova%1.s3db").arg(idProva).arg(nrampa);
    QSqlDatabase db= QSqlDatabase::addDatabase("QSQLITE",nomeDB);
    db.setDatabaseName(nomeDB);
    if (!db.open()){
        msg.setText(db.lastError().text());
        msg.show();
    }else{
        db.exec("create table test (campo int)");
    }
}
 
void myThread1::execCmd(QString cmd){
 
    QSqlDatabase::database(nomeDB).exec(cmd);
 
}
 
void myThread1::zipDB(){
    QString zipName;
    zipName=nomeDB;
    QSqlDatabase::removeDatabase(nomeDB);
    archive(zipName.replace(".s3db",".zip"),nomeDB,true);
    emit zipFileName(idProva, zipName);
    QFile(nomeDB).remove();
}

void myThread1::createDB(){
    nomeDB=QString("R%2_Prova%1.s3db").arg(idProva).arg(nrampa);
    QSqlDatabase db= QSqlDatabase::addDatabase("QSQLITE",nomeDB);
    db.setDatabaseName(nomeDB);
    if (!db.open()){
        msg.setText(db.lastError().text());
        msg.show();
    }else{
        db.exec("create table test (campo int)");
    }
}

void myThread1::execCmd(QString cmd){

    QSqlDatabase::database(nomeDB).exec(cmd);

}

void myThread1::zipDB(){
    QString zipName;
    zipName=nomeDB;
    QSqlDatabase::removeDatabase(nomeDB);
    archive(zipName.replace(".s3db",".zip"),nomeDB,true);
    emit zipFileName(idProva, zipName);
    QFile(nomeDB).remove();
}

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Now I use the QSqlDatabase db object only for set the database name, as variable and not as class member.

It run great.

Thanks

Michele