application crushes after performing selectionModel() from tableView

Hi guys,
i'm trying to get a current selected row from a tableview so i can retrieve data from database edit them and update the database.i'm using QSqlTableModel and QTableView.
When i run my application and push the editButton the application always crush,what seem to be a problem ,please help me here is the slot which cause the problem.

Code:

---

void customers::on_pushButton_2_clicked()
{
    const QModelIndexList list = m_ui->customerView->selectionModel()->selection().indexes();
    for (int i = 1; i < list.count(); i++)
    {
    QModelIndex index = list.at(i);
    int row = index.row();
    rows.insert(index.row());
    }
qDebug() << row;
 
 
 
     QSqlQuery query;
      query.exec(QString("SELECT * FROM customer where Id = row"));
       while (query.next()) {
 
          db_id =         query.value(0).toInt();
          db_LastName =      query.value(1).toString();
          db_FirstName =     query.value(2).toString();
          db_Category =        query.value(3).toString();
          db_Amount =   query.value(4).toString();
 
 
 
    }
 
 
  dialog = new newCustomer(this);
  dialog->editCustomer(db_LastName);
  int accepted = dialog->exec();
  if(accepted ==  1 )
  {
 
  }
}

---

One of m_ui, m_ui->customerView or m_ui->customerView->selectionModel() is null or your list has less than two elements.

the qDebug << name<< row; shows that the list contains 4 items shown below,whis is second row in a table view

"pop" 2
"pop" 2
"pop" 2
"pop" 2

but still the program crush .I modifies my code to one below here and i discovered that the "row" variable in a select statement is the one causing
the application to crush.....

Code:

---

void customers::on_pushButton_2_clicked()
{ 
    int row;
    const QModelIndexList list = m_ui->customerView->selectionModel()->selection().indexes();
    for (int i = 1; i < list.count(); i++)
    {
    QModelIndex index = list.at(i);
    row = index.row();
    QString name = model->record(row).value("LastName").toString();
    qDebug() << name << row ;
    }
 
 
     QSqlQuery query;
      query.exec(QString("SELECT * FROM customer where Id = " + row));  //when i remove the variable "row" the crush stops
       while (query.next()) {
 
          db_id =         query.value(0).toInt();
          db_LastName =      query.value(1).toString();
          db_FirstName =     query.value(2).toString();
          db_Category =        query.value(3).toString();
          db_Amount =   query.value(4).toString();
 
 
 
    }
 
 
  dialog = new newCustomer(this);
  dialog->editCustomer(db_LastName);
  int accepted = dialog->exec();
  if(accepted ==  1 )
  {
 
  }
}

---

You are adding an integer to a const char *. What effect do you think it has?