How to iterate through rows and columns of oracle result set using Oracle.jl?

Table Data:

SQL> SELECT * FROM SUBJECTS;

    ID SUBJECT
---------- --------------------------------------------------
     1 tamil
     2 english
     3 mathematics
     4 science
     5 social science

Julia script to fetch data:

import Oracle

global const dbHost = "localhost";
global const dbClientType = "thin";
global const dbName = "xe";
global const dbPort = "1521";
global const dbUserName = "ava";
global const dbUserPassword = "ava";
global const conn_str="//"*dbHost*":"*dbPort*"/"*dbName;

conn = Oracle.Connection(dbUserName, dbUserPassword, conn_str);
rs=Oracle.query(conn, "SELECT * FROM SUBJECTS");
#println(rs[1:3,1])
println(rs[1:3,"ID"])
#println(rs[1:3,2])
println(rs[1:3,"SUBJECT"])
Oracle.close(conn);

Please guide me in iterating through rows and columns using indices in for loop.