SELECT X.* FROM (SELECT CODE, RN FROM (SELECT A.CODE, @cnt := @cnt + 1 AS RN FROM SOMESCHEMA.SOMETABLE A, (SELECT @cnt := 0) C) T) X;

SELECT CODE, RN FROM (SELECT A.CODE, @cnt := @cnt + 1 AS RN FROM SOMESCHEMA.SOMETABLE A, (SELECT @cnt := 0) C) T;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

public class MariaTest2 {

	static String sql = "SELECT CODE, RN FROM (SELECT A.CODE, @cnt := @cnt + 1 AS RN FROM SOMESCHEMA.SOMETABLE A, (SELECT @cnt := 0) C) T";

//	static String sql = "SELECT X.* FROM (SELECT CODE, RN FROM (SELECT A.CODE, @cnt := @cnt + 1 AS RN FROM SOMESCHEMA.SOMETABLE A, (SELECT @cnt := 0) C) T) X";

	static String connUrl = "jdbc:mariadb://url";

	public static void main( String[] args ) throws SQLException {

		Connection conn = null;

		try {		

			conn = DriverManager.getConnection( connUrl );

			PreparedStatement stmt = conn.prepareStatement( sql );

			ResultSet rs = stmt.executeQuery();

			while ( rs.next() ) {

				System.out.print( rs.getLong( "CODE" ) );

				System.out.print( " " );

				System.out.print( rs.getLong( "RN" ) );

				System.out.println();

			}

			rs.close();

			stmt.close();

		} catch ( Exception e ) {

			// TODO Auto-generated catch block

			e.printStackTrace();

		} finally {

			conn.close();

		}

	}

}

String sql = "SELECT X.* FROM (SELECT CODE, RN FROM (SELECT A.CODE, @cnt := @cnt + 1 AS RN FROM SOMESCHEMA.SOMETABLE A) T) X";

PreparedStatement stmt;			

stmt = conn.prepareStatement( "SET @cnt := 0" );

stmt.executeQuery();			

stmt = conn.prepareStatement( sql );

ResultSet rs = stmt.executeQuery();