How to make QSortFilterProxyModel stop showing incomplete matches in search results?

I'm writing a database management application project for an animal shelter in which I use QSortFilterProxyModel to show search results. The problem is that the proxy model search shows even incomplete matches. For example if I have three animals with the ids 35, 388 and 3 and I search for an animal with id 3, it shows me all 3 of them because their ids all contain 3.

Here some of my code:

MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWindow) {
    ui->setupUi(this);

    proxyModel1 = new QSortFilterProxyModel(this);
    proxyModel1->setSourceModel(&model);
    ...
    connect(idEdit, SIGNAL(textChanged(const QString&)), this, SLOT(searchChanged()));
}

void MainWindow::searchChanged() {

    proxyModel1->setFilterRegExp(QRegExp(idEdit->text(), Qt::CaseInsensitive));
    proxyModel1->setFilterKeyColumn(0);
}

I need to stop that from happening.

Solution

The method that serves to filter an exact string does not exist so it must be implemented override the filterAcceptsRow() method:

class SortFilterProxyModel: public QSortFilterProxyModel
{
public:
    using QSortFilterProxyModel::QSortFilterProxyModel;
    QString fixedString() const{
        return m_fixedString;
    }

    void setFixedString(const QString &fixedString){
        if(m_fixedString == fixedString) return;
        m_fixedString = fixedString;
        invalidateFilter();
    }

protected:
    bool filterAcceptsRow(int source_row, const QModelIndex &source_parent) const override{
        if(m_fixedString.isEmpty())
            return true;
        QModelIndex ix = sourceModel()->index(source_row, filterKeyColumn(), source_parent);
        return ix.data().toString() == m_fixedString;
    }
private:
    QString m_fixedString;
};

MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWindow) {
    ui->setupUi(this);

    proxyModel1 = new SortFilterProxyModel(this);
    proxyModel1->setSourceModel(&model);
    connect(idEdit, &QLineEdit::textChanged, this, &MainWindow::searchChanged);    
}

void MainWindow::searchChanged() {
    proxyModel1->setFixedString(idEdit->text());
    proxyModel1->setFilterKeyColumn(0);
}