public String execute_query(String query, String col_name, boolean sel_str, boolean sel_int) {
		try {
			ResultSet rs;
			if (this.get_db_conn_state() == false)
				this.connect_loki_db();
			Statement stmt = this.get_db_connection().createStatement();
			String tn = null;
			if (sel_str ==  true) {
				rs = stmt.executeQuery(query);
				if(rs.next())
					tn = rs.getString(col_name);
			}
			else if (sel_int == true) {
				rs = stmt.executeQuery(query);
				if(rs.next())
					tn = String.valueOf(rs.getInt(col_name));
			}
			return tn;
		}catch(Exception e) {
			e.printStackTrace();
			return null;
		}
	}