Conditional statement within WP SQL query

Here is one approach:

$myrows = $wpdb->get_results( "SELECT first_name, surname, role, email, country, bio FROM members" );

foreach ( $myrows as $row ) {
    $first_name = $row->first_name;

    if ( ! empty( $row->bio ) ) {
        $first_name="<a href="#">" . $first_name . '</a><div class="bio" style="display: none;">' . $row->bio . '</div>';
    }

    echo "<tr><td>" . $first_name . "</td><td>" . $row->surname . "</td><td>" . $row->role . "</td><td>" . $row->email . "</td><td>" . $row->country . "</td></tr>";
}