String account = request.getParameter ( "account" );
String query = "SELECT * FROM users WHERE user.account = ? ";

PreparedStatement aux = sql_connect.prepareStatement ( query );
aux.setString ( 1, account );

try {
    ResultSet query_result = aux.executeQuery (  );

} catch ( Exception error ) {

    System.err.printf ( error.getMessage ( ) );
}







String account = request.getParameter ( "account" );

MessageDigest msg_digest = MessageDigest.getInstance ( "SHA-256" );
byte [] accountHash = msg_digest.digest ( account.getBytes (StandardCharsets.UTF_8) );

String query = "SELECT * FROM users WHERE user.account = ? ";

PreparedStatement aux = sql_connect.prepareStatement ( query );
aux.setString ( 1, accountHash );

try {

    ResultSet query_result = aux.executeQuery (  );

} catch ( Exception error ) {

    System.err.printf ( error.getMessage ( ) );
}