Sqlite commit says no transaction is open

Hello everyone ,

I have a problem and I couldn't find why? this is my program but every time commit returns false it says commit without any open transaction.

I use sqlite.
I havent any open query
All functions has local QSqlQuery so they killed after finishing
Without transaction everything works fine

Code:

// this is my sqlDB code
        // QSqlDatabase &DataManager::mainDB()
        //{
        //    return db;
        //}
        //
 
        CompanyMembersTable cmp(&sqlDB);
 
        QString lerror;
        if(sqlDB.mainDB().transaction())
        {
        if(cmp.removeMembers(customer.nationalcode))
        {
            if(cst.updateEntity(customer.id(), &customer)) {
                for(int i=0; i<ui->lstCompMem->count(); i++) {
                    QString nationlid = ui->lstCompMem->item(i)->data(Qt::UserRole).toString();
 
                    Customer cust;
                    cust.nationalid = nationlid;
 
                    if(cmp.insertMember(&customer, &cust) <= 0)
                    {
                        lerror = cmp.lastError();
                        break;
                    }
                }
                if(lerror.isEmpty() && sqlDB.mainDB().commit() ) {
                    QMessageBox::information(this, tr("Success Edit"), tr("Customer Updated successfully"));
                    emit saved();
                    return;
                }
                else if(lerror.isEmpty()) {
                    lerror = sqlDB.mainDB().lastError().text();
                }
            }
            else lerror = cst.lastError();
        }
        else lerror = cmp.lastError();
        }
        else lerror = sqlDB.mainDB().lastError().text();
 
        sqlDB.mainDB().rollback();
        QMessageBox::critical(this, tr("Edit Error"), tr("Error Happend.\n%1").arg(lerror), tr("OK"));
        return;

and I should mention that the below code work fine

Code:

CustomerTable cst(&sqlDB);
    CompanyMembersTable cmb(&sqlDB);
 
    sqlDB.mainDB().transaction();
    if(cst.insertEntity(&customer) > 0)
    {
        foreach (Customer cust, customer.members) {
            if(cmb.insertMember(&customer, &cust) <= 0)
            {
                goto ercust;
            }
        }
        if(sqlDB.mainDB().commit()) {
            QMessageBox::information(this, tr("Success Insert"), tr("Customer inserted successfully"));
            return;
        }
    }
 
ercust:
    QMessageBox::critical(this, tr("Error Insert"), tr("There is an error in inserting customer\n%1").arg(cst.lastError()));
    sqlDB.mainDB().rollback();

I want to know in witch situations a transaction would be canceled automatically.
thanks in advance