QCompleter* mycompletear = new QCompleter(this);
mycompletear->setCaseSensitivity(Qt::CaseInsensitive);
mycompletear->setModel(proxyModel);
mycompletear->setCompletionColumn(1);
mycompletear->setCompletionMode(QCompleter::UnfilteredPopupCompletion);
ui->comp_comb->setCompleter(mycompletear)