从Combox填充文本字段

Question

我尝试从组合框中填充文本字段，但收到以下错误消息，但不知道为什么？在youtube视频中有效

java.sql.SQLException: Column position '1' is out of range. The number of columns for this ResultSet is '0'. at .
    at org.apache.derby.client.am.SQLExceptionFactory40.getSQLException(Unknown Source)
    at org.apache.derby.client.am.SqlException.getSQLException(Unknown Source)
    at org.apache.derby.client.am.ColumnMetaData.getColumnType(Unknown Source)
    at org.apache.derby.client.am.PreparedStatement.setString(Unknown Source)

try {
    String s = jComboBoxKunde.getSelectedItem().toString();
    String sql = "Select * from ROOT.KUNDE where NAME = '?'";
    PreparedStatement pst = con.prepareStatement(sql);
    pst.setString(1, s);
    rst = pst.executeQuery(sql);

    while (rst.next()) {
        jTFauftraggeber.setText(rst.getString(1));
        jTFtelefonnummer.setText(rst.getString(2));
        jTFemail.setText(rst.getString(3));
    }

} catch (SQLException ex) {
    Logger.getLogger(MainWindow.class.getName()).log(Level.SEVERE, null, ex);
}

我的rst有什么问题吗？